JP7706101B2 - Screen Printing Equipment - Google Patents

Description

This disclosure relates to a screen printing device.

A screen printing device in a component mounting line where electronic components are mounted on a board performs screen printing to supply solder for joining the components to the board. The screen printing device raises the board while holding both sides of the board with holding members, and brings the top surface of the board into contact with the bottom surface of the mask. The screen printing device sucks the mask through suction holes formed in the holding members, and ensures sufficient adhesion between the mask and the board by bringing them into close contact, and then slides a squeegee over the mask to transfer solder through the mask openings to the lands on the board that are the target of solder supply.

In this type of screen printing method, if the warped portion of the substrate is close to the suction position of the mask suction, the screen printing device corrects the warp of the substrate by sucking the mask using the substrate clamp members. However, if the warped portion of the substrate is far from the suction position of the mask suction, it is difficult for the screen printing device to correct the warp of the substrate by sucking the mask using the substrate clamp members, and this substrate warpage makes it difficult to obtain sufficient adhesion between the mask and the substrate. For this reason, the screen printing device sometimes causes printing defects by transferring solder to the lands on the substrate with the solder having entered the gap between the mask and the substrate.

To prevent such printing defects, Patent Document 1 discloses a technique in which a mask support surface is placed on the outside of a pair of sides of the substrate that are not held by the substrate holding member, and a concave substrate support table in which the substrate support surface that supports the underside of the substrate and the mask support surface are integrated is used to adsorb the mask between the substrate holding member and the mask support surface that is part of the concave member, thereby improving adhesion between the mask and the substrate.

JP 2016-179669 A

However, the screen printing device described in Patent Document 1 uses a concave substrate support table in which the mask support surface and substrate support surface are integrated, which necessitates the creation of multiple substrate support tables of different sizes to correspond to the dimensions of the substrate, resulting in an increased cost.

The present disclosure has been devised in consideration of the above-mentioned conventional circumstances, and aims to provide a screen printing device that can more effectively correct the warping of a substrate and improve adhesion between the substrate and mask to achieve high-quality printing.

The present disclosure provides a screen printing device that includes a pair of substrate transport conveyors that transport a substrate to a predetermined position, a bottom support member that supports the substrate at the predetermined position from below, a pair of substrate clamp members that hold opposing sides of the substrate, and at least one mask suction unit, and is disposed between the pair of substrate transport conveyors. The mask suction unit is arranged to suction a mask in a predetermined suction area along a direction intersecting the sides by driving a negative pressure source. The mask suction unit brings the substrate into contact with the mask having pattern holes formed therein, and prints paste on the substrate through the pattern holes. The mask suction unit has at least one first suction hole in a contact surface that contacts the mask, and the lifting unit is arranged on the same surface as the installation surface of the bottom support member.

The present disclosure also provides a screen printing device comprising a pair of substrate transport conveyors for transporting a substrate to a predetermined position, a lower support member for supporting the substrate at the predetermined position from below, a pair of substrate clamp members for holding opposing sides of the substrate, and at least one mask suction unit, a mask suction unit disposed between the pair of substrate transport conveyors and suctioning a mask in a predetermined suction area along a direction intersecting the side by driving a negative pressure source, a printing unit for contacting the substrate with the mask having pattern holes formed therein and printing a paste on the substrate through the pattern holes, and a lifting unit for moving the mask suction unit so as to be able to rise and fall, the mask suction unit contacts the mask and has the suction area based on the number or arrangement of at least one first suction hole capable of suctioning the mask, the mask suction unit has at least one first suction hole on a contact surface that contacts the mask, and the lifting unit is disposed on the same surface as the installation surface of the lower support member.

The present invention makes it possible to more effectively correct warpage in the substrate, improving adhesion between the substrate and the mask and achieving high-quality printing.

FIG. 1 is a front view of a screen printing apparatus according to an embodiment; FIG. 1 is a partial plan view of a screen printing apparatus according to an embodiment; FIG. 1 is a partial plan view of a screen printing apparatus according to an embodiment; FIG. 1 is a partial side view of a screen printing apparatus according to an embodiment; FIG. 1 is a diagram showing a first configuration example of a mask suction unit according to an embodiment; FIG. 13 is a diagram showing a second configuration example of a mask suction unit in the embodiment; FIG. 13 is a diagram showing a third configuration example of a mask suction unit in the embodiment; FIG. 13 shows a fourth configuration example of a mask suction unit in the embodiment. FIG. 13 is a diagram showing a fifth configuration example of a mask suction unit in the embodiment; FIG. 13 is a diagram showing a sixth configuration example of a mask suction unit in the embodiment; FIG. 13 is a diagram showing a seventh configuration example of a mask suction unit in the embodiment; 4C and 4E are perspective views of the mask suction portion shown in FIG. SS cross-sectional view of the mask suction portion shown in FIG. 5. A cross-sectional view of the mask suction portion shown in FIG. FIG. 1 is a diagram for explaining an example of a mask suction unit according to an embodiment; FIG. 13 is a diagram for explaining an example of the suction operation of the mask suction unit in the embodiment; FIG. 13 is a diagram for explaining an example of the suction operation of the mask suction unit in the embodiment;

Below, with reference to the drawings as appropriate, an embodiment specifically disclosing the screen printing apparatus according to the present disclosure will be described in detail. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. Note that the attached drawings and the following explanation are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

In addition, in each figure with directional arrows, the X-axis indicates the depth direction. The Y-axis indicates the left-right direction. The Z-axis indicates the up-down direction (vertical direction). The X-axis and Y-axis are perpendicular to each other and are included in the horizontal plane. The Z-axis is included in the vertical plane.

First, the structure of the screen printing apparatus 1 will be described with reference to Figures 1, 2A, and 2B. Figure 1 is a front view of the screen printing apparatus 1 according to the embodiment. Figure 2A is a partial plan view of the screen printing apparatus 1 according to the embodiment. Figure 2B is a partial plan view of the screen printing apparatus 1 according to the embodiment.

In FIG. 1, the screen printing apparatus 1 includes a substrate holding stage moving mechanism 2, a screen printing unit 3, and a substrate holding stage 4, with the screen printing unit 3 disposed above the substrate holding stage 4, which is raised and lowered in the Z-axis and -Z-axis directions by the substrate holding stage moving mechanism 2.

The substrate holding stage moving mechanism 2 moves or rotates the substrate holding stage 4 in a horizontal plane (XY plane) and moves the substrate holding stage 4 up and down (Z axis direction). The substrate holding stage 4 is composed of a first base plate 5, a vertical frame 6, a substrate transport mechanism 7, a lower support member lifting mechanism 9, a second base plate 10, and a lower support member 12. The first base plate 5 is moved or rotated in a horizontal plane (XY plane) and moved up and down (Z axis direction) by the substrate holding stage moving mechanism 2. The vertical frame 6 and the lower support member lifting mechanism 9 are arranged on the upper surface side of the first base plate 5. The substrate transport mechanism 7 is held at the upper end of the vertical frame 6. The substrate clamp mechanism 8 is arranged above the substrate transport mechanism 7. The second base plate 10 is raised and lowered in the vertical direction (Z axis direction) by the lower support member lifting mechanism 9. The lower support member 12 is placed on the upper surface of the second base plate 10 and supports from below the lower surface of the substrate 11 transported by the substrate transport mechanism 7.

The substrate transport mechanism 7 has two substrate transport conveyors 7a arranged parallel to each other along the X-axis direction, and supports both opposing ends of the underside of the substrate 11 from below by the substrate transport conveyors 7a to transport the substrate 11 to a predetermined substrate transport position. The substrate transport mechanism 7 transports the substrate 11 from the upstream side (-X-axis direction) to the downstream side (X-axis direction). The substrate 11 brought in from the upstream side is transported by the substrate transport mechanism 7 to a predetermined substrate transport position and is positioned by the substrate holding stage moving mechanism 2. After the substrate 11 is subjected to screen printing processing by the screen printing unit 3, it is transported downstream by the substrate transport mechanism 7.

The screen printing apparatus 1 drives the substrate holding stage moving mechanism 2 to raise the first base plate 5 of the substrate holding stage 4 in the vertical direction (Z-axis direction or -Z-axis direction). By raising the first base plate 5 in the upward direction (Z-axis direction), the screen printing apparatus 1 can raise the substrate 11 held by the substrate transport mechanism 7 configured integrally with the first base plate 5 to the height at which the mask 13 of the screen printing unit 3 is held (the height at which the lower surface of the mask 13 is located, for example, height H0 shown in FIG. 9).

The mask suction section 20 is disposed on the upper surface of the second base plate 10, which is raised and lowered by the lower support member lifting mechanism 9, and is composed of at least one mask suction unit 20a connected to a negative pressure source 30. The mask suction section 20 suctions the mask 13 with the negative pressure generated by driving the connected negative pressure source 30.

As shown in FIG. 2B, the upper surface of the mask suction unit 20a has a contact surface 20d that contacts the lower surface of the mask 13. The contact surface 20d has suction holes 20b for suctioning the mask 13. In the present embodiment, the shape of the suction holes 20b is shown as a circle as an example, but may be other shapes such as an ellipse or a rectangle. The suction holes 20b communicate with the mask suction unit side hole 20k and are connected to the negative pressure source 30 by the suction tube 20c connected to the mask suction unit side hole 20k. The suction holes 20b suck and suction the lower surface of the mask 13 located above the contact surface 20d or in contact with the contact surface 20d, when the mask suction unit side hole 20k and the suction tube 20c are driven to a negative pressure by the negative pressure source 30. The mask suction unit 20 is arranged to sandwich the lower support member 12 (see FIG. 3) along the transport direction (X-axis direction) of the substrate 11.

Now, with reference to Figures 6 and 8, various structures of the mask suction unit 20a constituting the mask suction section 20 will be described. In this embodiment, the mask suction unit 20a uses three types of mask suction units 20a1, 20a2, and 20a3, which differ in the presence or absence of suction holes 20b, mask suction unit side holes 20k, suction paths 20f, convex portions 20o, concave portions 20p, etc., and in their shapes.

As shown in FIG. 6, the mask suction unit 20a1 has a contact surface 20d that contacts the lower surface of the mask 13. The contact surface 20d is formed on the upper surface of the mask suction unit 20a1 and has a suction hole 20b for suctioning the lower surface of the mask 13. The suction hole 20b is formed extending in the -Z axis direction and communicates with the mask suction unit side hole 20k formed along a direction approximately parallel to the contact surface 20d. The suction hole 20b is connected to the negative pressure source 30 by the suction tube 20c and the mask suction unit side hole 20k, and the inside of the suction tube 20c and the mask suction unit side hole 20k becomes negative pressure when the negative pressure source 30 is driven, and the lower surface of the mask 13 located above the contact surface 20d or in contact with the contact surface 20d is suctioned. Note that the shape of the suction hole 20b in this embodiment is shown as a circular shape as an example, but it may be other shapes such as an ellipse or a rectangle.

When the mask suction unit 20a1 is located closest to the negative pressure source 30, one of the two through holes formed by the mask suction unit side hole 20k (i.e., the through hole located on the Y-axis side in FIG. 6) is connected to the suction tube 20c and functions as a suction path 20f that enables suction (suction) at the suction hole 20b. Also, when the mask suction unit 20 is composed of two or more mask suction units 20a, the other of the two through holes formed by the mask suction unit side hole 20k (i.e., the through hole located on the -Y-axis side in FIG. 6) spatially connects the mask suction unit side hole 20k of the next connected mask suction unit 20a (i.e., the other mask suction unit 20a connected in the direction away from the negative pressure source 30) to the negative pressure source 30 via the mask suction unit side hole 20k formed by penetrating in the Y-axis direction, forming a suction path 20f (see FIG. 6). In addition, the mask adsorption unit 20a1 is placed at a position closest to the negative pressure source 30 when the mask adsorption section 20 is composed of two mask adsorption units 20a each, and is placed at a position other than the end farthest from the negative pressure source 30 when the mask adsorption section 20 is composed of three or more mask adsorption units 20a each.

As shown in FIG. 6, the mask suction unit 20a2 has a contact surface 20d that contacts the lower surface of the mask 13. The contact surface 20d is formed on the upper surface of the mask suction unit 20a2 and has a suction hole 20b for suctioning the lower surface of the mask 13. The suction hole 20b is formed extending in the -Z axis direction and communicates with the mask suction unit side hole 20k formed along a direction approximately parallel to the contact surface 20d. The mask suction unit side hole 20k in the mask suction unit 20a2 is formed semi-penetrating the mask suction unit 20a2 in the Y axis direction. The suction hole 20b is connected to the negative pressure source 30 by the suction tube 20c and the mask suction unit side hole 20k, and the inside of the suction tube 20c becomes negative pressure when the negative pressure source 30 is driven, and the lower surface of the mask 13 located above the contact surface 20d or in contact with the contact surface 20d is suctioned.

When the mask suction unit 20a2 is placed in a position closest to the negative pressure source 30, the through hole formed by the mask suction unit side hole 20k is connected to the suction tube 20c and functions as a suction path 20f that enables suction (suction) at the suction hole 20b. In addition, when the mask suction section 20 is composed of two mask suction units 20a, the through hole formed by the mask suction unit side hole 20k is placed in a position farthest from the negative pressure source 30 and is spatially connected to the through hole of the mask suction unit side hole 20k of the mask suction unit 20a connected to the front side (i.e., the negative pressure source 30 side).

As shown in FIG. 6, the mask suction unit 20a3 has a contact surface 20d that contacts the underside of the mask 13, and is formed along a direction approximately parallel to the contact surface 20d, and communicates with a mask suction unit side hole 20k that penetrates the mask suction unit 20a3 in the Y-axis direction.

When the mask suction unit 20a3 is located closest to the negative pressure source 30, one of the two through holes formed by the mask suction unit side hole 20k (i.e., the through hole located on the Y-axis side in FIG. 6) is connected to the suction tube 20c and functions as the suction path 20f. Also, when the mask suction unit 20 is composed of two or more mask suction units 20a, the other of the two through holes formed by the mask suction unit side hole 20k (i.e., the through hole located on the -Y-axis side in FIG. 6) spatially connects the mask suction unit side hole 20k of the next connected mask suction unit 20a (i.e., the other mask suction unit 20a connected in the direction away from the negative pressure source 30) to the negative pressure source 30 via the mask suction unit side hole 20k formed by penetrating in the Y-axis direction, and is connected to the mask suction unit side hole 20k of the other mask suction units 20a1, 20a2 to form the suction path 20f (see FIG. 6). In addition, the mask adsorption unit 20a3 is placed at a position closest to the negative pressure source 30 when the mask adsorption section 20 is composed of two mask adsorption units 20a each, and is placed at a position other than the end position farthest from the negative pressure source 30 when the mask adsorption section 20 is composed of three or more mask adsorption units 20a each.

As described above, the mask suction section 20 is composed of one or more mask suction units 20a (specifically, mask suction units 20a1, 20a2, and 20a3). The mask suction section 20 is composed of a combination of the three types of mask suction units 20a1, 20a2, and 20a3 described above, so that the suction force can be adjusted more easily. The mask suction section 20 can further improve its suction force by arranging the mask suction units 20a1 and 20a2 having suction holes 20b at positions where the adhesion of the mask 13 to the substrate 11 should be increased (i.e., where the mask 13 should be more strongly suctioned), such as a portion where the density or number of pattern holes 13a is high (i.e., a portion where the substrate 11 is likely to warp greatly due to the reflow process). Therefore, the screen printing device 1 can increase the force pressing the substrate 11 in the -Z axis direction by suctioning the lower surface of the mask 13 with the mask suction unit 20a, and can further correct the warping of the substrate 11 caused by the mask 13.

The mask suction section 20 may be connected to the substrate clamping member 8a of the substrate clamping mechanism 8 by branching the suction pipe 20c connected to the mask suction unit 20a. In other words, the screen printing apparatus 1 uses the mask suction section 20 and the substrate clamping member 8a to suction the lower surface of the mask 13 by the same negative pressure source 30. As a result, by using the mask suction section 20 and the substrate clamping member 8a to suction the lower surface of the mask 13, the screen printing apparatus 1 can increase the force with which the suctioned mask 13 presses the substrate 11 in the -Z axis direction compared to when the lower surface of the mask 13 is suctioned using either the mask suction section 20 or the substrate clamping member 8a. Therefore, the screen printing apparatus 1 can more effectively correct the warping of the substrate 11 caused by the mask 13 by increasing the force with which the substrate 11 is pressed in the -Z axis direction.

The lower support member 12 provided on the upper surface of the second base plate 10 is raised and lowered in the vertical direction (Z-axis direction, -Z-axis direction) by the drive of the lower support member lifting mechanism 9, and is raised and lowered so as to approach or move away from the substrate 11 held by the substrate transport mechanism 7. The lower support member 12 abuts against the lower surface of the substrate 11, thereby supporting the lower surface of the substrate 11 from below.

The mask suction portion 20 is provided on the upper surface of the second base plate 10, and is raised and lowered in the vertical direction (Z-axis direction, -Z-axis direction) by driving the lower support member lifting mechanism 9 in the same way as the lower support member 12, so as to approach or move away from the substrate 11 held by the substrate transport mechanism 7. Note that the contact surface 20d of the mask suction portion 20 does not contact the underside of the substrate 11 at the height at which the lower support member 12 abuts on the underside of the substrate 11 (height H2 shown in FIG. 9) (details will be described later).

The substrate clamping mechanism 8 is disposed above the substrate transport mechanism 7. The substrate clamping mechanism 8 includes a pair of substrate clamping members 8a facing each other in the X-axis direction, and by moving one of the substrate clamping members 8a forward or backward in the Y-axis direction or the -Y-axis direction, the pair of substrate clamping members 8a clamps and holds and fixes a pair of opposing sides of the substrate 11 (i.e., a pair of opposing sides along the X-axis direction). As shown in FIG. 2B, each of the pair of substrate clamping members 8a includes a plurality of suction holes 8c on the upper surface for adsorbing the mask 13. Each of the plurality of suction holes 8c is provided along a pair of opposing sides of the substrate 11 (i.e., the X-axis direction). The negative pressure source connected to each of the plurality of suction holes 8c may be a negative pressure source 30 connected to the mask adsorption unit 20, or may be another negative pressure source (not shown).

When the negative pressure source connected to each of the multiple suction holes 8c is a negative pressure source 30 connected to the mask suction unit 20, the negative pressure source 30 branches the suction pipe 20c connected to the mask suction unit 20a and connects to the substrate clamp members 8a of a pair of substrate clamp mechanisms 8 described below. This allows the screen printing device 1 to achieve suction of the underside of the mask 13 using the mask suction unit 20 and the substrate clamp members 8a with a single negative pressure source 30.

As described above, the screen printing apparatus 1 according to the present embodiment sucks and adsorbs the lower surface of the mask 13 using the suction holes 20b in the mask adsorption unit 20 and each of the suction holes 8c in the substrate clamp member 8a. As a result, the screen printing apparatus 1 can adsorb the lower surface of the mask 13 to the substrate 11 from four directions (X-axis direction, -X-axis direction, Y-axis direction, and -Y-axis direction) using the mask adsorption unit 20 and the substrate clamp member 8a with one negative pressure source 30, so that the substrate 11 can be more effectively corrected regardless of the direction in which it is warped. Therefore, by adsorbing the lower surface of the mask 13 using the mask adsorption unit 20 and the substrate clamp member 8a, the screen printing apparatus 1 can increase the force with which the adsorbed mask 13 presses the substrate 11 in the -Z-axis direction compared to the case in which the lower surface of the mask 13 is adsorbed using either the mask adsorption unit 20 or the substrate clamp member 8a. In other words, the screen printing apparatus 1 can more effectively correct the warping of the substrate 11 caused by the mask 13 by increasing the force with which the substrate 11 is pressed in the -Z-axis direction.

The screen printing apparatus 1 holds the sides of the substrate 11 in the Y-axis and -Y-axis directions with the substrate clamp members 8a, and while restricting the movement of the substrate 11, drives the substrate holding stage movement mechanism 2 to raise the substrate 11 in the Z-axis direction. The screen printing apparatus 1 drives the substrate holding stage movement mechanism 2 to position the substrate 11 at a height position where the upper surface of the substrate 11 and the lower surface of the mask 13 come into contact. In this way, while holding the substrate 11 with the substrate clamp members 8a on the substrate holding stage 4, the screen printing apparatus 1 raises the substrate holding stage movement mechanism 2 in the Z-axis direction, bringing the substrate 11 close to the mask 13 from below, and positions the substrate 11 at a predetermined height where the upper surface of the substrate 11 comes into contact with the lower surface of the mask 13.

The screen printing apparatus 1 drives the substrate holding stage moving mechanism 2 to raise the mask suction portion 20 together with the substrate 11 held by the substrate clamp member 8a. The mask suction portion 20 is positioned at a predetermined height where the contact surface 20d contacts the underside of the mask 13, or at a predetermined height (height H0 shown in FIG. 9) where the mask suction portion 20 can suction the underside of the mask 13 (i.e., the mask suction portion 20 can suction the underside of the mask 13 by driving the negative pressure source 30) but the contact surface 20d does not contact the underside of the mask 13.

Next, the screen printing unit 3 will be described. In the example shown in Figures 1, 2A, and 2B, the screen printing unit 3 is formed in a flat plate shape and includes, for example, a rectangular mask 13 (see Figure 2A). The frame 14 is fixed at a predetermined height above the substrate holding stage moving mechanism 2 and is disposed on the outer edge of the mask 13 to stretch and hold the mask 13 at a predetermined height. The mask 13 has a number of pattern holes 13a (see Figure 2A) formed therein that correspond to the shape and position of each of the multiple electrodes 11a (see Figure 2B) formed on the substrate 11.

A squeegee head 15 is disposed above the mask 13. The squeegee head 15 has a horizontally formed plate 15a, and a squeegee lifting mechanism 15c that raises and lowers each of the multiple squeegees 15b on the plate 15a. The squeegee lifting mechanism 15c has each of multiple rods 15d that extend downward (in the -Z axis direction). Each of the multiple rods 15d has a squeegee 15b attached to its lower end. Each of the multiple squeegees 15b is driven by the squeegee lifting mechanism 15c that is integrally configured via the rod 15d, and is lowered to a height that contacts the upper surface of the mask 13 to print the solder paste on the board 11.

Next, the positional relationship between the mask suction unit 20, the lower support member 12, and the substrate 11 will be described with reference to FIG. 3. FIG. 3 is a partial side view of the screen printing device 1 according to the embodiment.

Figure 3(a) is a diagram showing the positional relationship between the mask suction portion 20 and the lower support member 12 or the substrate 11 when the dimension α1 in the transport direction (X-axis direction) of the substrate 11 is equal to or smaller than the dimension β1 in the X-axis direction of the lower support member 12 (i.e., dimension α1 ≦ dimension β1). Each of the multiple mask suction portions 20 is positioned at a predetermined distance in each of the X-axis direction and the -X-axis direction from the lower support member 12, which is placed on the upper surface of the second base plate 10, with the lower support member 12 in between.

Figure 3(b) is a diagram showing the positional relationship between the mask suction portion 20 and the lower support member 12 or the substrate 11 when the dimension α2 in the transport direction (X-axis direction) of the substrate 11 is greater than the dimension β2 in the X-axis direction of the lower support member 12 (i.e., dimension α2 > dimension β2). Each of the multiple mask suction portions 20 is positioned at a predetermined distance in each of the X-axis direction and the -X-axis direction from the lower support member 12, which is placed on the upper surface of the second base plate 10, with the lower support member 12 in between.

Here, the arrangement of each of the pair of mask adsorption parts 20 will be described. Each of the distances γ1 and γ2 shown in FIG. 3 is the distance between the center points of the suction holes 20b provided in at least one mask adsorption unit 20a of each of the pair of mask adsorption parts 20 arranged in the -X-axis direction and the X-axis direction of the lower support member 12. Each of the multiple mask adsorption parts 20 is arranged so that the distance γ1>dimension β1 when the dimension α1≦dimension β1, and is arranged so that the distance γ2>dimension α2>dimension β2 when the dimension α2>dimension β2. As a result, even if the dimension of the substrate 11 is larger than the dimension of the lower support member (i.e., the dimension α2>dimension β2), the entire upper surface of the substrate 11 can be adsorbed with the mask 13 covering it. Also, as a result, even if each of the multiple mask adsorption parts 20 is raised to approximately the same height as the substrate 11 by each of the substrate holding stage moving mechanism 2 and the lower support member lifting mechanism 9, interference between the mask adsorption part 20 and the substrate 11 can be avoided.

Note that, although an example is shown in which each of the pair of mask suction portions 20 shown in FIG. 3 is positioned at a predetermined distance apart from the lower support member 12 in both the X-axis direction and the -X-axis direction, this is not limiting. Each of the pair of mask suction portions 20 may be positioned at any distance apart from the lower support member 12, with the distance being different depending on the number and positions of each of the multiple pattern holes 13a formed in the mask 13. This allows the screen printing device 1 to adjust the suction strength according to the pattern holes 13a formed in each of the masks 13.

Next, referring to Figures 4A to 4G, examples of the configuration of each of the multiple mask adsorption units 20a constituting the mask adsorption section 20 arranged on the second base plate 10 (see Figures 1 and 2) will be described. Figure 4A is a diagram showing a first example of the configuration of the mask adsorption section 20 in the embodiment. Figure 4B is a diagram showing a second example of the configuration of the mask adsorption section 20 in the embodiment. Figure 4C is a diagram showing a third example of the configuration of the mask adsorption section 20 in the embodiment. Figure 4D is a diagram showing a fourth example of the configuration of the mask adsorption section 20 in the embodiment. Figure 4E is a diagram showing a fifth example of the configuration of the mask adsorption section 20 in the embodiment. Figure 4F is a diagram showing a sixth example of the configuration of the mask adsorption section 20 in the embodiment. Figure 4G is a diagram showing a seventh example of the configuration of the mask adsorption section 20 in the embodiment. It goes without saying that the configuration of the mask adsorption section 20 is not limited to the examples of the configurations shown in Figures 4A to 4G.

Each of the pair of mask suction parts 20 is disposed between each of the pair of substrate transport mechanisms 7 and on each of the X-axis and -X-axis directions (i.e., the left and right directions of the paper) of the substrate 11. Each of the pair of mask suction parts 20 is raised in the Z-axis direction by the substrate holding stage moving mechanism 2 and positioned at a predetermined height at which the lower surface of the mask 13 comes into contact with the contact surface 20d of the mask suction part 20, or at a predetermined height at which the mask suction part 20 can suction the lower surface of the mask 13 by driving the negative pressure source 30. The screen printing device 1 raises each of the pair of mask suction parts 20 to a predetermined height, and then drives the negative pressure source 30 to suction the lower surface of the mask 13 from the directions corresponding to the four sides of the mask 13, which is formed into a substantially rectangular shape, by each of the pair of mask suction parts 20 and each of the pair of substrate clamping mechanisms 8.

Each of the pair of mask adsorption sections 20 includes at least one mask adsorption unit 20a. Furthermore, at least one mask adsorption unit 20a constituting each of the pair of mask adsorption sections 20 includes at least one suction hole 20b.

The mask suction unit 20a is provided with a suction path 20f (see Figures 6 and 7) for transmitting the negative pressure generated by driving the negative pressure source 30 to the suction hole 20b. The suction path 20f is provided along a direction parallel to the contact surface 20d. Note that when the mask suction section 20 is composed of multiple mask suction units 20a, the suction hole 20b does not have to be provided in each of the mask suction units 20a, and it is sufficient that at least one mask suction unit 20a has a suction hole 20b.

The pair of mask suction parts 20 shown in FIG. 4A shows an example in which four mask suction units 20a each having a suction hole 20b on the contact surface 20d are connected (linked) to be integrally configured. The pair of mask suction parts 20 suction the underside of the mask 13 in the suction area 20e (area indicated by the dashed line around the suction hole 20b) including the vicinity of the suction hole 20b of each mask suction unit 20a. Here, the suction area 20e is an area including at least the suction hole 20b, and can suction the underside of the mask 13 by transmitting the negative pressure generated by driving the negative pressure source 30 to the suction hole 20b through the suction path 20f communicating with the suction tube 20c.

The pair of mask suction parts 20 shown in FIG. 4B shows an example in which six mask suction units 20a, each having a suction hole 20b in the contact surface 20d, are connected (linked) to be integrally configured. The pair of mask suction parts 20 adsorb the underside of the mask 13 in an adsorption area 20e (the area indicated by the dashed line around the suction hole 20b) including the vicinity of the suction hole 20b of each mask suction unit 20a.

Each of FIG. 4A and FIG. 4B is a diagram showing an example in which the number of mask suction units 20a constituting the mask suction section 20 and the arrangement position of the mask suction section 20 in the X-axis direction (i.e., the distance between the substrate 11 and the mask suction section 20) are changed in accordance with the dimensions of the substrate 11 in the Y-axis direction. Specifically, an example is shown in which the dimensions of the substrate 11 in the X-axis direction and the Y-axis direction shown in FIG. 4A are equal to or smaller than the dimensions of the substrate 11 in the X-axis direction and the Y-axis direction shown in FIG. 4B. As a result, even when printing solder on a substrate 11 whose dimensions (size) have changed due to overheating such as a reflow process, or a substrate 11 of different dimensions (sizes), the worker can more appropriately suction the mask 13 by adjusting the number of mask suction units 20a constituting the mask suction section 20 and the arrangement position of the mask suction section 20 (i.e., the distance between the substrate 11 and the mask suction section 20).

Specifically, when printing solder on a board 11 having smaller dimensions, the worker reduces the number of mask suction units 20a constituting the mask suction section 20 and adjusts the distance between each of the pair of mask suction sections 20 and the board 11. On the other hand, when printing solder on a board 11 having larger dimensions, the worker increases the number of mask suction units 20a constituting the mask suction section 20 and adjusts the distance between each of the pair of mask suction sections 20 and the board 11.

Even when the screen printing device 1 prints solder on a substrate 11 having dimensions (sizes) different from the dimensions of the substrate 11 before the reflow process, if the number and positions of each of the pair of mask suction parts 20 installed during the solder printing process on the substrate 11 before the reflow process can achieve adhesion between the upper surface of the substrate 11 and the lower surface of the mask 13, the number and positions of the mask suction units 20a do not need to be adjusted (changed) by the operator, or only one of them may be adjusted (changed).

The pair of mask adsorption units 20 shown in FIG. 4C is an example of a mask adsorption unit 20 that is composed of three mask adsorption units 20a each having a suction hole 20b on the contact surface 20d, and two mask adsorption units 20a each having no suction hole 20b on the contact surface 20d. Each of the pair of mask adsorption units 20a only needs to have a suction hole 20b in at least one of the multiple mask adsorption units 20a. By increasing or decreasing the number of mask adsorption units 20a (specifically, mask adsorption units 20a1 and 20a2) that do not have a suction hole 20b among the multiple mask adsorption units 20a that constitute the mask adsorption unit 20, or adjusting the arrangement to change the adsorption area 20e, the adsorption force (suction force) of the mask adsorption unit 20 against the lower surface of the mask 13 can be adjusted.

The pair of mask adsorption parts 20 shown in FIG. 4D shows an example in which the mask adsorption units 20a constituting the mask adsorption part 20 are different. For example, the mask adsorption part 20 installed in the −X-axis direction with respect to the substrate 11 is composed of three mask adsorption units 20a each having suction holes 20b on three contact surfaces 20d, and one mask adsorption unit 20a each having no suction holes 20b on the contact surface 20d, and suction pipes 20c are connected to two of the four mask adsorption units 20a.

For example, the mask adsorption section 20 installed in the X-axis direction with respect to the substrate 11 is composed of three mask adsorption units 20a each having suction holes 20b on three contact surfaces 20d, and two mask adsorption units 20a each having no suction holes 20b on the contact surface 20d, and a suction tube 20c is connected to one of these five mask adsorption units 20a. As a result, each of the pair of mask adsorption sections 20 can adjust the adsorption force (suction force) of the mask adsorption section 20 against the lower surface of the mask 13 and the area of the adsorption area 20e according to the size, arrangement, etc. of the pattern holes 13a formed in the mask 13, and more appropriately adsorb the lower surface of the mask 13.

The pair of mask suction parts 20 shown in FIG. 4E is an example of a mask suction unit 20 having a suction hole 20b on the contact surface 20d and three mask suction units 20a connected to a suction tube 20c. Each of the mask suction units 20a can suction the lower surface of the mask 13 independently by using the suction hole 20b. The mask suction units 20a are arranged at equal intervals along the Y-axis direction, and the suction holes 20b on the contact surface 20d communicate with the mask suction unit side hole 20k and the suction path 20f (see FIG. 6). Each of the mask suction units 20a has a suction path 20f connected to the suction tube 20c, and is driven by the negative pressure source 30 connected to the suction tube 20c to suction the lower surface of the mask 13 located on the contact surface 20d.

The pair of mask suction parts 20 shown in FIG. 4F is an example in which each of the pair of mask suction units 20a has a suction hole 20b on the contact surface 20d and is connected to a suction tube 20c. Each of the mask suction units 20a can independently suction the lower surface of the mask 13 by the suction hole 20b, and are arranged at equal intervals in the Y-axis direction, with the suction holes 20b on the contact surface 20d communicating with the mask suction unit side hole 20k and the suction path 20f (see FIG. 6). Each of the mask suction units 20a has a suction path 20f connected to the suction tube 20c, and suctions the lower surface of the mask 13 located on the contact surface 20d by driving the negative pressure source 30 connected to the suction tube 20c.

The number of mask suction units 20a constituting the pair of mask suction sections 20 shown in FIG. 4E is greater than the number of mask suction units 20a constituting the pair of mask suction sections 20 shown in FIG. 4F. The closer the spacing between the mask suction units 20a having suction holes 20b, the greater the suction force of the mask suction section 20 to suction the underside of the mask 13. Therefore, for example, when the substrates 11 shown in FIG. 4E and FIG. 4F have the same dimensions, the suction force of the pair of mask suction sections 20 shown in FIG. 4E is greater than the suction force of the pair of mask suction sections 20 shown in FIG. 4F.

The pair of mask suction parts 20 shown in FIG. 4G is an example in which each of the mask suction parts 20 is composed of four mask suction units 20a each having a suction hole 20b on the contact surface 20d and connected to a suction tube 20c. Each of the mask suction units 20a can independently suction the underside of the mask 13 by means of the suction hole 20b, and are arranged at equal intervals along the Y-axis direction, with the suction holes 20b on the contact surface 20d communicating with the mask suction unit side hole 20k and the suction path 20f (see FIG. 6). Each of the mask suction units 20a has a suction path 20f connected to the suction tube 20c, and is driven by a negative pressure source 30 connected to the suction tube 20c to suction the underside of the mask 13 located on the contact surface 20d.

The number of mask suction units 20a constituting the pair of mask suction sections 20 shown in FIG. 4E is less than the number of mask suction units 20a constituting the pair of mask suction sections 20 shown in FIG. 4G. Therefore, for example, if the substrates 11 shown in FIG. 4E and FIG. 4G have the same dimensions, the suction force of the pair of mask suction sections 20 shown in FIG. 4E is less than the suction force of the pair of mask suction sections 20 shown in FIG. 4G.

As described above, the suction area 20e and suction force of the mask suction section 20 can be adjusted based on the number or arrangement of the mask suction units 20a (specifically, mask suction units 20a1 and 20a2) having the suction holes 20b. The type, number, or arrangement of the mask suction units 20a of the mask suction section 20 does not need to be adjusted for each dimension of the board 11. For example, even when printing solder paste on boards 11 of different dimensions, if sufficient adhesion between the upper surface of the board 11 and the lower surface of the mask 13 required for the printing process can be obtained, the mask suction section 20 may be used as is without adjusting the type, number, or arrangement of the mask suction units 20a.

The mask suction section 20 shown in Figures 4A to 4C and Figures 4E to 4G has been described as a case in which the mask suction units 20a that can individually suction the lower surface of the mask 13 are arranged at equal intervals along the Y-axis direction. However, it is not necessary for all mask suction units 20a to be arranged at equal intervals, as in the mask suction section 20 shown in Figure 4D. In addition, as in the pair of mask suction sections 20 shown in Figure 4D, the type, number, or arrangement of the mask suction units 20a that make up each of the pair of mask suction sections 20 do not have to be the same. This makes it easier for the worker to adjust the configuration of the mask suction section 20 so that sufficient adhesion between the upper surface of the board 11 and the lower surface of the mask 13 required for printing solder paste is obtained based on the dimensions of the board 11 or the pattern holes 13a of the mask 13.

Figure 5 is a perspective view of the mask suction unit 20 shown in Figures 4C and 4E. Figure 5(a) shows a perspective view of the mask suction unit 20 shown in Figure 4C. Figure 5(b) shows a perspective view of the mask suction unit 20 shown in Figure 4E.

The mask adsorption section 20 shown in FIG. 5(a) is constructed by combining a plurality of mask adsorption units 20a into one unit. Specifically, the mask adsorption section 20 shown in FIG. 5(a) is constructed by combining mask adsorption unit 20a1, mask adsorption unit 20a3, mask adsorption unit 20a1, mask adsorption unit 20a3, and mask adsorption unit 20a2 in this order in the -Y axis direction (the direction from the back of the page to the front of the page).

The mask suction unit leg 20h is disposed on the second base plate 10 (not shown). The mask suction unit leg 20h is connected to the mask suction unit 20a by the mask suction unit support part 20i that extends from above the mask suction unit leg 20h, and supports the mask suction unit 20a.

The mask suction unit 20 is connected to the suction tube 20c of the mask suction unit side hole 20k (see FIG. 6) of the mask suction unit 20a1 that is located at the back of the paper in the Y-axis direction among the multiple mask suction units 20a. The mask suction unit 20 connects the suction hole 20b of each mask suction unit 20a to the negative pressure source 30 through the mask suction unit side hole 20k (see FIG. 6) formed inside each mask suction unit 20a to form a suction path 20f, and adsorbs the underside of the mask 13 by driving the negative pressure source 30. Note that the suction tube 20c does not need to be connected to the mask suction unit 20a located at the back as shown in FIG. 5(a), but may be connected to any one of the multiple mask suction units 20a that constitute the mask suction unit 20. In addition, the mask suction unit 20a to which the suction tube 20c is connected is not limited to any one of the multiple mask suction units 20a, and may be connected to two or more mask suction units 20a.

The mask adsorption section 20 shown in FIG. 5(b) is composed of individual mask adsorption units 20a that are not connected to each other. Specifically, the mask adsorption section 20 shown in FIG. 5(a) is composed of three mask adsorption units 20a2 that are not connected to each other.

In the mask suction section 20, the suction tube 20c is connected to the suction path 20f (see Figures 6 and 7) of each mask suction unit 20a. Each mask suction unit 20a has a suction hole 20b connected to a negative pressure source 30, and adsorbs the underside of the mask 13 by driving the negative pressure source 30. In the mask suction unit 20a2, the suction path 20f formed inside is connected to the negative pressure source 30 via the suction tube 20c, and the suction tube 20c communicates with the negative pressure source 30 through the mask suction unit side hole 20k to adsorb the underside of the mask 13.

Next, the suction paths of the mask suction unit 20 shown in Figs. 4C and 4E will be described with reference to Figs. 6 and 7. Fig. 6 is an S-S cross-sectional view of the mask suction unit 20 shown in Fig. 5. Fig. 7 is a T-T cross-sectional view of the mask suction unit 20 shown in Fig. 5. Note that the suction paths referred to here refer to the paths from each of the suction holes 20b of each mask suction unit 20a to the negative pressure source 30.

First, the structure of the mask suction unit 20a will be described. Note that the fixing member 20m and the side hole 20r into which the fixing member 20m is inserted are only shown in some of the mask suction units 20a, and are omitted in the other mask suction units 20a.

The side hole 20r is provided in communication with the threaded hole 20s into which the mask suction unit support part 20i is screwed from the side of the mask suction unit 20a. The side hole 20r is provided with a fixing member 20m that fixes the screwed state of the mask suction unit support part 20i. The fixing member 20m is, for example, a hexagonal socket set screw, and by pressing the mask suction unit support part 20i screwed into the threaded hole 20s in the Y-axis direction, it suppresses the rotation of the mask suction unit 20a due to the release of the screwed state between the threaded hole 20s and the mask suction unit support part 20i. Note that the fixing member 20m is not limited to the above-mentioned hexagonal socket set screw, etc., and may be any member that can press the mask suction unit support part 20i.

The mask suction unit support part 20i has male threads at the top and bottom, and is screwed into the threaded hole 20s formed on the bottom surface (-Z-axis surface) of the mask suction unit 20a and the threaded hole 20t formed on the top surface of the mask suction unit leg part 20h that faces the bottom surface of the mask suction unit 20a. The mask suction unit support part 20i is rotated in a predetermined direction by the operator to adjust the height of the contact surface 20d and the suction hole 20b of the mask suction unit 20a in the Z-axis direction. The mask suction unit support part 20i may be fixed by gluing to the threaded hole 20s. In such a case, the side hole 20r and the fixing member 20m are unnecessary. The upper part of the mask suction unit support part 20i does not need to be male threaded.

The means for lifting the mask suction unit 20a in the Z-axis direction is not limited to the mask suction unit support part 20i. For example, the mask suction unit 20a may be provided with a lifting means such as a cylinder below the mask suction unit 20a to achieve lifting in the Z-axis direction.

The mask suction unit 20a is connected to other mask suction units 20a by the convex portion 20о and the concave portion 20p described below. If the bonding force between the convex portion 20о and the concave portion 20p, or the balance of the contact surface 20d with respect to the underside of the mask 13, is sufficient to adsorb the underside of the mask 13, the mask suction unit legs 20h and the mask suction unit support portion 20i may be omitted.

The mask suction unit leg 20h has a leg-side hole 20l formed in the surface that contacts the second base plate 10, which is the installation surface of the mask suction unit 20a, toward the inside of the mask suction unit leg 20h (for example, the Z-axis direction shown in FIG. 6), and accommodates a magnet member 20j that can fix the mask suction unit 20a. The magnet member 20j may not be accommodated in the leg-side hole 20l and may be coupled to the lower surface of the mask suction unit leg 20h. In such a case, the magnet member 20j may be formed to have the same size and shape as the lower surface of the mask suction unit leg 20h. The height of the magnet member 20j may be the same as the depth of the leg-side hole 20l, or may be smaller than the depth of the leg-side hole 20l. This allows the operator to more easily attach and detach the mask adsorption unit 20a to and from the second base plate 10, or adjust the position of each of the one or more mask adsorption units 20a that make up the mask adsorption section 20, using the magnet member 20j on the underside of the mask adsorption unit leg 20h.

In the mask suction unit 20 shown in FIG. 6, the mask suction unit side hole 20k of the mask suction unit 20a1 to which the suction tube 20c is connected, and the mask suction unit side hole 20k and suction hole 20b of the other mask suction unit 20a connected to this mask suction unit side hole 20k function as a suction path for sucking the mask 13. This allows the mask suction unit 20 to suck the underside of the mask 13 by driving the negative pressure source 30.

The mask suction unit 20 shown in FIG. 7 suctions the underside of the mask 13 with the suction holes 20b of each of the three mask suction units 20a2. The negative pressure sources 30 connected to each of the three mask suction units 20a2 may be the same negative pressure source 30 or different negative pressure sources (not shown).

Next, the structure for connecting the multiple mask suction units 20a will be described with reference to FIG. 8. FIG. 8 is a diagram illustrating an example of connecting the mask suction units 20a in the embodiment.

Figure 8 (a) is a diagram showing a bonding surface 20n where mask adsorption units 20a are bonded to each other. A through hole of the mask adsorption unit side hole 20k formed toward the inside of the mask adsorption unit 20a penetrates the center of the bonding surface 20n, and a convex portion 20o and a concave portion 20p are formed around this mask adsorption unit side hole 20k. Note that the number and positions of the convex portions 20o and the concave portions 20p shown in Figure 8 are merely examples and are not limited to these.

Each of the protrusions 20o is provided so as to be able to fit into a position corresponding to each of the recesses 20p formed in the other mask suction unit 20a, as shown in FIG. 8(b). Each of the protrusions 20o fits into each of the recesses 20p formed in the other mask suction unit 20a, thereby connecting the two mask suction units 20a together.

Each of the recesses 20p is a depression that faces the inside of the mask suction unit 20a and is arranged so that it can fit into a position corresponding to each of the protrusions 20о formed on the other mask suction units 20a, as shown in FIG. 8(b).

The shapes of the convex portion 20o and the concave portion 20p are not limited to the spherical shape shown in FIG. 8, and may be, for example, cylindrical, square prism, triangular pyramid, cone, etc. In addition, in order to prevent erroneous coupling between the mask adsorption units 20a (for example, coupling with the suction hole 20b facing the second base plate 10 side, coupling with the mask adsorption unit side hole portion 20k of the mask adsorption units 20a not connected, etc.), as shown in FIG. 8, two convex portions 20o or concave portions 20p are arranged on the upper part of the coupling surface 20n, and one convex portion 20o or concave portion 20p is formed on the lower part of the coupling surface 20n, thereby limiting the coupling direction between the mask adsorption units 20a. Therefore, the mask adsorption unit 20a in this embodiment has different numbers of convex portions 20o and concave portions 20p on the upper and lower parts (or left and right) of the coupling surface 20n, which can further prevent erroneous coupling between the mask adsorption units 20a.

The protrusion 20o formed on one of the opposing joining surfaces 20n may be made of a magnetic material. In this case, the worker can use the magnetic force that attracts the recess 20p formed on the other joining surface 20n toward the protrusion 20o to join the mask suction units 20a together, making it easier to join and separate them.

Figure 8 (b) is a diagram showing the height relationship between the convex portion 20о and the concave portion 20p formed on each of the joining surfaces 20n of the two mask suction units 20a. The convex portion 20о and the concave portion 20p are formed to a height that allows them to fit together.

Figure 8(c) is a diagram showing how the two mask suction units 20a are joined together. The two mask suction units 20a are positioned by fitting the convex portion 20o and the concave portion 20p together, fixing the relative positions of the joining surfaces 20n of each other. This allows the two mask suction units 20a to be joined together without variation in the height of the contact surfaces 20d of the two mask suction units 20a.

The operation procedure until the mask suction unit 20 suctions the lower surface of the mask 13 will be described with reference to Figures 9 and 10. Figure 9 is a diagram for explaining an example of the suction operation of the mask suction unit 20 in the embodiment. Figure 10 is a diagram for explaining an example of the suction operation of the mask suction unit 20 in the embodiment. Note that Figure 9 is a side view of the screen printing device 1 as viewed from the X-axis direction. Figure 10 is a cross-sectional view showing the UU cross section, VV cross section, and WW cross section of the screen printing device 1 cut along each of the cross-sectional lines shown in Figure 9. Note that the screen printing device 1 shown in Figures 9 and 10 shows the configuration necessary to explain the operation procedure until the mask suction unit 20 suctions the lower surface of the mask 13, and some of the configuration is not shown.

The screen printing device 1 shown in Figures 9(a) and 10(a) shows a state in which a substrate 11 is brought in from the upstream side and transported to a predetermined substrate transport position by the substrate transport conveyor 7a of the substrate transport mechanism 7, and is positioned above the lower support member 12 by the substrate holding stage movement mechanism 2.

As shown in Figures 9(a) and 10(a), the screen printing apparatus 1 positions the substrate 11 above the lower support member 12 using the substrate holding stage movement mechanism 2, and then drives the lower support member lifting mechanism 9 as shown in Figures 9(b) and 10(b). The screen printing apparatus 1 uses the lower support member lifting mechanism 9 to raise the second base plate 10 from the current height H1 to height H2 at which the upper surface of the lower support member 12 abuts against the lower surface of the substrate 11. The lower support member 12 supports the lower surface of the substrate 11 from below at the height H2 position.

Since the mask suction unit 20 is provided on the upper surface of the second base plate 10, it is raised in the Z-axis direction by driving the lower support member lifting mechanism 9. The height of the mask suction unit leg 20h of the mask suction unit 20 may be adjusted so that the height of the contact surface 20d of the mask suction unit 20 is the same as the height of the upper surface of the substrate 11 at height H2, or the height of the mask suction unit leg 20h may be adjusted so that the lower surface of the mask 13 can be suctioned and the height of the contact surface 20d of the mask suction unit 20 after lifting is lower than the height of the upper surface of the substrate 11 as shown in FIG. 9.

The screen printing apparatus 1 shown in FIG. 9(c) and FIG. 10(c) drives the substrate holding stage moving mechanism 2 to raise the lower support member lifting mechanism 9 in the Z-axis direction. In the screen printing apparatus 1, while holding the substrate 11 at height H0, the substrate holding stage moving mechanism 2 raises the lower support member lifting mechanism 9 from the current height H3 to height H4 at which the upper surface of the substrate 11 abuts against the lower surface of the mask 13. Note that the height of the mask suction unit leg 20h of the mask suction unit 20 may be adjusted so that the height of the contact surface 20d and the upper surface of the substrate 11 are the same height at height H2, or the height of the mask suction unit leg 20h may be adjusted so that the lower surface of the mask 13 can be suctioned and the height of the contact surface 20d of the mask suction unit 20 after the lift is lower than the height of the upper surface of the substrate 11 as shown in FIG. 9.

In the screen printing apparatus 1, the substrate holding stage moving mechanism 2 raises the lower support member lifting mechanism 9 from the current height H3 to a height H4 at which the upper surface of the substrate 11 abuts against the lower surface of the mask 13, and then the negative pressure source 30 is driven to suck the lower surface of the mask 13 through the suction holes 8c of the substrate clamping mechanism 8 and the suction holes 20b of the mask suction unit 20. As a result, the screen printing apparatus 1 according to this embodiment can more effectively correct the warping of the substrate 11 even if the substrate 11 is warped by sucking the mask 13 having a substantially rectangular shape from four directions against the substrate 11. Note that the screen printing apparatus 1 according to this embodiment can more effectively correct the warping of the substrate 11 in the Y-axis direction by sucking the lower surface of the mask 13 through a pair of mask suction units 20 arranged in the X-axis direction with the substrate 11 between them, even if the substrate 11 is warped along a direction perpendicular to the X-axis direction in which the suction holes 8c are provided (i.e., the Y-axis direction). Therefore, the screen printing device 1 can improve the adhesion between the mask 13 and the substrate 11 even if the substrate 11 is warped, thereby making it possible to reduce the gap between the mask 13 and the substrate 11. This allows the screen printing device 1 to prevent solder from being transferred to the lands on the substrate 11 when solder has entered the gap, thereby further reducing the occurrence of printing defects.

As described above, the screen printing device 1 according to the embodiment includes a pair of substrate transport conveyors 7a that transport the substrate 11 to a predetermined position, a lower support member 12 that supports the substrate 11 from below at the predetermined position, a pair of substrate clamp members 8a that hold the opposing sides of the substrate 11, a mask suction unit 20 that is disposed between the pair of substrate transport conveyors 7a and that suctions the mask 13 in a predetermined suction area 20e along a direction intersecting the side by driving a negative pressure source 30, and a screen printing unit 3 (an example of a printing unit) that brings the substrate 11 into contact with the mask 13 in which pattern holes 13a are formed, and prints paste on the substrate 11 through the pattern holes 13a.

As a result, the screen printing apparatus 1 according to the embodiment can correct the warping of the substrate 11 by sucking the mask 13 from four directions (i.e., the opposing sides of the substrate 11 (X-axis direction) and the direction perpendicular to these sides (Y-axis direction)) against the substrate 11 even if the substrate 11 is warped in the direction perpendicular to the X-axis direction in which the suction holes 8c are provided. Therefore, the screen printing apparatus 1 can improve the adhesion between the mask 13 and the substrate 11 even if the substrate 11 is warped, thereby making it possible to reduce the gap between the mask 13 and the substrate 11. As a result, the screen printing apparatus 1 can prevent the solder from being transferred to the land on the substrate 11 with the solder having entered the gap, thereby further reducing the occurrence of printing defects.

As a result of the above, the mask suction unit 20 provided in the screen printing device 1 according to the embodiment has an adsorption area 20e based on the number or arrangement of at least one suction hole 20b (an example of a first suction hole) that contacts the mask 13 and can adsorb the mask 13. As a result, the screen printing device 1 according to the embodiment can adjust the adsorption area 20e based on the number or arrangement of the suction holes 20b. Therefore, in the screen printing device 1, each of the pair of mask suction units 20 can adjust the adsorption force (suction force) of the mask suction unit 20 against the lower surface of the mask 13 and the area of the adsorption area 20e according to the size, arrangement, etc. of the pattern hole 13a formed in the mask 13, and can more appropriately adsorb the lower surface of the mask 13 and more appropriately correct the warping of the substrate 11.

As described above, the mask suction section 20 of the screen printing device 1 according to the embodiment is composed of at least one mask suction unit 20a, and has at least one suction hole 20b on the contact surface 20d that contacts the mask 13. This allows the screen printing device 1 according to the embodiment to suck and adsorb the lower surface of the mask 13.

As described above, each of the multiple mask adsorption units 20a provided in the screen printing apparatus 1 according to the embodiment is connected to each other to form one mask adsorption section 20, and at least one mask adsorption unit 20a is connected to the negative pressure source 30 to adsorb the mask 13. As a result, the screen printing apparatus 1 according to the embodiment can adjust the magnitude of the adsorption force (suction force) of the mask adsorption section 20 against the underside of the mask 13 and the area of the adsorption area 20e according to the size of the substrate 11, the size or arrangement of the pattern holes 13a formed in the mask 13, etc., and can more appropriately adsorb the underside of the mask 13 and more appropriately correct the warping of the substrate 11.

Furthermore, as described above, the mask suction unit 20a provided in the screen printing apparatus 1 according to the embodiment has a mask suction unit side hole 20k (an example of a space) inside the mask suction unit 20a along the contact surface 20d, and the mask suction unit side hole 20k forms a suction path 20f connecting the suction hole 20b and the negative pressure source 30. As a result, the screen printing apparatus 1 according to the embodiment can achieve suction (suction) of the mask 13 with a single negative pressure source 30, even when the mask suction unit 20 has multiple suction holes 20b.

Furthermore, as described above, when the mask adsorption section 20 of the screen printing apparatus 1 according to the embodiment is configured with two or more mask adsorption units 20a, each of the two or more mask adsorption units 20a is individually connected to the negative pressure source 30 to adsorb the mask 13. This allows the screen printing apparatus 1 according to the embodiment to further improve the adsorption force (suction force) of the mask adsorption section 20.

As described above, the screen printing apparatus 1 according to the embodiment further includes a mask suction unit support part 20i and a mask suction unit leg part 20h (an example of a lift part) that move the mask suction unit 20a so that it can be raised and lowered. The mask suction unit support part 20i and the mask suction unit leg part 20h are arranged on the same surface as the installation surface of the lower support member 12 (i.e., the upper surface of the second base plate 10). As a result, the screen printing apparatus 1 according to the embodiment can adjust the height of the contact surface 20d and the suction hole 20b of the mask suction part 20 to a height corresponding to the thickness of the substrate 11, etc.

In addition, as described above, the mask adsorption unit support portion 20i and the mask adsorption unit leg portion 20h provided in the screen printing apparatus 1 according to the embodiment have a magnet member 20j (an example of a magnetic material) on the surface (i.e., the bottom surface of the mask adsorption unit leg portion 20h) that contacts the installation surface (i.e., the upper surface of the second base plate 10) on which the lower support member 12 is installed. This allows the operator to more easily change or adjust the configuration and arrangement of the mask adsorption portion 20.

As described above, the screen printing apparatus 1 according to the embodiment further includes a plurality of suction holes 8c (an example of a second suction hole) that are provided in each of the pair of substrate clamp members 8a and that adsorb the substrate 11 along the side direction. The suction holes 20b of the mask adsorption unit 20 and the suction holes 8c of the substrate clamp members 8a are connected to a negative pressure source 30 to adsorb the mask 13. As a result, the screen printing apparatus 1 according to the embodiment can adsorb the lower surface of the mask 13 to the substrate 11 from four directions (X-axis direction, -X-axis direction, Y-axis direction, and -Y-axis direction) using the mask adsorption unit 20 and the substrate clamp members 8a with one negative pressure source 30, so that the substrate 11 can be more effectively corrected regardless of the direction in which it is warped. Therefore, by adsorbing the underside of the mask 13 using the mask adsorption unit 20 and the substrate clamping member 8a, the screen printing apparatus 1 can increase the force with which the adsorbed mask 13 presses the substrate 11 in the -Z axis direction compared to when the underside of the mask 13 is adsorbed using either the mask adsorption unit 20 or the substrate clamping member 8a. In other words, by increasing the force with which the screen printing apparatus 1 presses the substrate 11 in the -Z axis direction, the screen printing apparatus 1 can more effectively correct the warping of the substrate 11 caused by the mask 13.

Furthermore, as described above, the suction holes 20b of the mask suction unit 20 provided in the screen printing apparatus 1 according to the embodiment are arranged at positions corresponding to the positions of the pattern holes 13a of the mask 13. As a result, the screen printing apparatus 1 according to the embodiment can adjust the magnitude of the suction force (suction force) of the mask suction unit 20 against the underside of the mask 13 and the area of the suction region 20e according to the size of the substrate 11 and the size or arrangement of the pattern holes 13a formed in the mask 13, etc., and can more appropriately suction the underside of the mask 13 and more appropriately correct the warping of the substrate 11.

Although various embodiments have been described above with reference to the attached drawings, the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications, amendments, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also fall within the technical scope of the present disclosure. Furthermore, the components in the various embodiments described above may be combined in any manner as long as it does not deviate from the spirit of the invention.

This disclosure is useful as a screen printing device that can more effectively correct warping of a substrate and improve adhesion between the substrate and mask to achieve high-quality printing.

REFERENCE SIGNS LIST 1 Screen printing device 2 Substrate holding stage moving mechanism 3 Screen printing section 4 Substrate holding stage 7 Substrate transport mechanism 7a Substrate transport conveyor 8 Substrate clamp mechanism 8a Substrate clamp member 8c Suction hole 11 Substrate 12 Lower support member 13 Mask 13a Pattern hole 20 Mask suction section 20a Mask suction unit 20b Suction hole 20d Contact surface 20e Suction area 20f Suction path 20k Mask suction unit side hole 20i Mask suction unit support section 20j Magnet member 30 Negative pressure source

Claims (8)

A pair of substrate transport conveyors for transporting substrates to a predetermined position;
a lower support member that supports the substrate at the predetermined position from below;
a pair of substrate clamp members for holding opposing sides of the substrate;
a mask suction section including at least one mask suction unit, disposed between the pair of substrate transport conveyors, and configured to suction a mask in a predetermined suction region along a direction intersecting with the side edges by being driven by a negative pressure source;
a printing unit that brings the substrate into contact with the mask having pattern holes formed therein, and prints a paste onto the substrate through the pattern holes;
a lifting unit that moves the mask suction unit in an up-down direction,
the mask suction unit has at least one first suction hole on a contact surface that contacts the mask,
The lifting unit is disposed on the same plane as the installation surface of the lower support member.
Screen printing equipment. A pair of substrate transport conveyors for transporting substrates to a predetermined position;
a lower support member that supports the substrate at the predetermined position from below;
a pair of substrate clamp members for holding opposing sides of the substrate;
a mask suction section including at least one mask suction unit, disposed between the pair of substrate transport conveyors, and configured to suction a mask in a predetermined suction region along a direction intersecting with the side edges by being driven by a negative pressure source;
a printing unit that brings the substrate into contact with the mask having pattern holes formed therein, and prints a paste onto the substrate through the pattern holes;
a lifting unit that moves the mask suction unit in an up-down direction,
the mask suction unit contacts the mask and has the suction region based on the number or arrangement of at least one first suction hole capable of suctioning the mask,
the mask suction unit has at least one first suction hole in a contact surface that comes into contact with the mask,
The lifting unit is disposed on the same plane as the installation surface of the lower support member.
Screen printing equipment. the plurality of mask suction units are coupled to each other to form one of the mask suction sections, and at least one of the mask suction units is connected to the negative pressure source to suction the mask;
3. The screen printing apparatus according to claim 1 or 2. the mask suction unit has a space inside the mask suction unit along the contact surface, and the space forms a suction path connecting the first suction hole and the negative pressure source;
The screen printing apparatus according to claim 3 . When the mask suction section is configured by two or more mask suction units, each of the two or more mask suction units is individually connected to the negative pressure source and suctions the mask.
3. The screen printing apparatus according to claim 1 or 2. The lifting unit has a magnetic body on a surface that contacts the installation surface.
The screen printing apparatus according to claim 5 . a plurality of second suction holes provided in each of the pair of substrate clamp members for adsorbing the mask along the side direction,
the first suction hole and the second suction hole are connected to the negative pressure source to adsorb the mask;
The screen printing apparatus according to claim 2 . the first suction hole is disposed at a position corresponding to a position of the pattern hole of the mask;
The screen printing apparatus according to claim 2 .

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