Screen printing apparatus

Abstract

To correct warp of a substrate more efficiently and achieve high-quality printing by improving adhesion between the substrate and a mask.SOLUTION: A screen printer comprises: a pair of substrate carrying conveyors that carry a substrate to a predetermined position; a lower receiving member supporting the substrate at a predetermined position from below; a pair of substrate clamping members holding opposite side edges of the substrate; a mask sucking unit disposed between the pair of substrate carrying conveyors and that sucks the mask in a predetermined suction area along a direction intersecting the side edges by driving a negative pressure source; and a printing unit that prints a paste on the substrate through a pattern hole by bringing the substrate into contact with the mask having the pattern hole formed therein.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a screen printing apparatus.

Background Art

[0002] A screen printing apparatus in a component mounting line for mounting electronic components on a substrate performs screen printing for supplying solder for bonding components to the substrate. The screen printing apparatus raises the substrate while holding both sides of the substrate by a holding member, and brings the upper surface of the substrate into contact with the lower surface of the mask. The screen printing apparatus sucks the mask through suction holes formed in the holding member, ensures sufficient adhesion between the mask and the substrate by bringing the mask and the substrate into close contact, and then slides the squeegee on the mask to transfer solder to lands on the substrate that are targets for solder supply through mask openings.

[0003] In such a screen printing method, when a warped portion of the substrate is close to the suction position for mask suction, the screen printing apparatus corrects the warp of the substrate by sucking the mask using a substrate clamp member. However, when the warped portion of the substrate is far from the suction position for mask adsorption, it is difficult for the screen printing apparatus to correct the warp of the substrate by sucking the mask using the substrate clamp member, and sufficient adhesion between the mask and the substrate cannot be obtained due to this warp of the substrate. For this reason, in the screen printing apparatus, printing defects may occur when solder is transferred to lands on the substrate with solder having entered the gap between the mask and the substrate.

[0004] In order to prevent such printing defects, Patent Document 1 discloses a technique in which a mask support surface is disposed outside a pair of side edges of a substrate that is not held by a substrate holding member, and a concave substrate support base in which a substrate support surface for supporting the lower surface of the substrate and the mask support surface are integrated adsorbs the mask with the substrate holding member and the mask support surface that is a part of the concave member, thereby enhancing the adhesion between the mask and the substrate.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-179669 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] However, in the screen printing apparatus described in Patent Document 1, since a concave substrate support base in which the mask support surface and the substrate support surface are integrated is used, it is necessary to prepare a plurality of substrate support bases of different sizes corresponding to the dimensions of the substrate, resulting in an increase in cost.

[0007] The present disclosure has been devised in view of the above-described conventional circumstances, and an object thereof is to provide a screen printing apparatus that can more effectively correct the warp of a substrate, improve the adhesion between the substrate and the mask, and achieve high-quality printing. [Means for Solving the Problems]

[0008] The present disclosure includes a pair of substrate conveyance conveyors that convey a substrate to a predetermined position, a lower receiving member that supports the substrate at the predetermined position from below, a pair of substrate clamp members that hold opposite side edges of the substrate, and at least one mask suction unit. The mask suction unit is disposed between the pair of substrate conveyance conveyors and adsorbs a mask in a predetermined suction region along a direction intersecting the side edges by driving a negative pressure source. A printing unit that contacts the substrate with the mask having pattern holes formed therein and prints paste onto the substrate through the pattern holes, and a lifting unit that moves the mask suction unit up and down. 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 receiving member, and provides a screen printing apparatus.

[0009] In addition, the present disclosure further includes a pair of substrate transfer conveyors for transferring a substrate to a predetermined position, a lower receiving member for supporting the substrate at the predetermined position from below, a pair of substrate clamp members for holding opposite side edges of the substrate, and at least one mask suction unit. The mask suction unit is disposed between the pair of substrate transfer conveyors and adsorbs a mask in a predetermined suction region along a direction intersecting the side edges by driving a negative pressure source. The present disclosure further includes a printing unit for bringing the substrate into contact with the mask having pattern holes and printing paste onto the substrate through the pattern holes, and a lifting unit for movably lifting the mask suction unit up and down. The mask suction portion has the suction region based on the number or arrangement of at least one first suction hole that contacts the mask and can adsorb the mask. The mask suction portion has at least one first suction hole on a contact surface that contacts the mask. The lifting unit is disposed on the same surface as the installation surface of the lower receiving member, thereby providing a screen printing apparatus.

Advantages of the Invention

[0010] According to the present invention, warping of the substrate can be more effectively corrected, adhesion between the substrate and the mask can be improved, and high-quality printing can be achieved.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4A

Figure 4B

Figure 4C

Figure 4D

Figure 4E

Figure 4F

Figure 4G

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments specifically disclosing the screen printing apparatus according to the present disclosure will be described in detail with reference to the drawings as appropriate. However, a more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and duplicate descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and it is not intended to limit the subject matter described in the claims thereby.

[0013] In addition, in each figure in which an arrow indicating a direction is drawn, 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 the Y-axis are orthogonal to each other and are included in the horizontal plane. The Z-axis is included in the vertical plane.

[0014] First, with reference to FIGS. 1, 2A, and 2B, the structure of the screen printing apparatus 1 will be described. FIG. 1 is a front view of the screen printing apparatus 1 according to the embodiment. FIG. 2A is a partial plan view of the screen printing apparatus 1 according to the embodiment. FIG. 2B is a partial plan view of the screen printing apparatus 1 according to the embodiment.

[0015] 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. The screen printing unit 3 is disposed above the substrate holding stage 4 that is moved up and down in the Z-axis direction and -Z-axis direction by the substrate holding stage moving mechanism 2.

[0016] The substrate holding stage moving mechanism 2 moves or rotates the substrate holding stage 4 in a horizontal plane (within the XY plane) and also moves the substrate holding stage 4 in the vertical direction (Z-axis direction). The substrate holding stage 4 is composed of a first base plate 5, a vertical frame 6, a substrate transfer mechanism 7, a lower receiving member lifting mechanism 9, a second base plate 10, and a lower receiving member 12. The first base plate 5 is moved or rotated in a horizontal plane (within the XY plane) and moved in the vertical direction (Z-axis direction) by the substrate holding stage moving mechanism 2. The vertical frame 6 and the lower receiving member lifting mechanism 9 are disposed on the upper surface side of the first base plate 5. The substrate transfer mechanism 7 is held at the upper end of the vertical frame 6. The substrate clamping mechanism 8 is disposed above the substrate transfer mechanism 7. The second base plate 10 is moved up and down in the vertical direction (Z-axis direction) by the lower receiving member lifting mechanism 9. The lower receiving member 12 is disposed on the upper surface of the second base plate 10 and supports the lower surface of the substrate 11 conveyed by the substrate transfer mechanism 7 from below.

[0017] The substrate transfer mechanism 7 includes two substrate transfer conveyors 7a arranged in parallel with each other along the X-axis direction, supports both opposite ends of the lower surface of the substrate 11 from below by the substrate transfer conveyors 7a, and transfers the substrate 11 to a predetermined substrate transfer position. The substrate transfer mechanism 7 transfers the substrate 11 from the upstream side (-X-axis direction) to the downstream side (X-axis direction). The substrate 11 carried in from the upstream side is transferred to a predetermined substrate transfer position by the substrate transfer mechanism 7 and positioned by the substrate holding stage moving mechanism 2. Note that after the screen printing process by the screen printing unit 3 is performed on the substrate 11, the substrate 11 is transferred to the downstream side by the substrate transfer mechanism 7.

[0018] 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 transfer 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, the height H0 shown in FIG. 9).

[0019] The mask suction unit 20 is disposed on the upper surface of the second base plate 10 that is moved up and down by the lower receiving 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 unit 20 suctions the mask 13 with the negative pressure generated by driving the connected negative pressure source 30.

[0020] 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 is provided with suction holes 20b for sucking the mask 13. Note that, as an example, the shape of the suction holes 20b in the present embodiment is circular, but other shapes such as an ellipse or a rectangle may also be used. The suction holes 20b communicate with the mask suction unit side hole portion 20k and are connected to the negative pressure source 30 through a suction pipe 20c connected to the mask suction unit side hole portion 20k. When the negative pressure source 30 is driven, the inside of the mask suction unit side hole portion 20k and the suction pipe 20c becomes a negative pressure, and the lower surface of the mask 13 located above or in contact with the contact surface 20d is sucked and adsorbed. The mask suction portion 20 is arranged so as to sandwich a lower receiving member 12 (see FIG. 3) along the conveyance direction (X-axis direction) of the substrate 11.

[0021] Here, with reference to FIGS. 6 and 8, various structures of the mask suction unit 20a that constitutes the mask suction portion 20 will be described. In the present embodiment, three types of mask suction units 20a1, 20a2, and 20a3 having different presence or absence and shapes of suction holes 20b, mask suction unit side hole portions 20k, suction paths 20f, convex portions 20o, or concave portions 20p are used.

[0022] 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 is provided with suction holes 20b for sucking the lower surface of the mask 13. The suction holes 20b extend in the -Z axis direction and communicate with the mask suction unit side hole portion 20k formed along a direction substantially parallel to the contact surface 20d. The suction holes 20b are connected to the negative pressure source 30 through the suction pipe 20c and the mask suction unit side hole portion 20k. When the negative pressure source 30 is driven, the inside of the suction pipe 20c and the mask suction unit side hole portion 20k becomes a negative pressure, and the lower surface of the mask 13 located above or in contact with the contact surface 20d is sucked and adsorbed. Note that, as an example, the shape of the suction holes 20b in the present embodiment is circular, but other shapes such as an ellipse or a rectangle may also be used.

[0023] When the mask suction unit 20a1 is arranged at the position closest to the negative pressure source 30, one of the two through-holes formed by the mask suction unit side hole portion 20k (that is, the through-hole located on the Y-axis direction side in FIG. 6) functions as a suction path 20f to which the suction pipe 20c is connected to enable suction (adsorption) at the suction hole 20b. Further, when the mask suction portion 20 is composed of two or more mask suction units 20a, the other through-hole of the two through-holes formed by the mask suction unit side hole portion 20k (that is, the through-hole located on the -Y-axis direction side in FIG. 6) spatially connects the mask suction unit side hole portion 20k of the next-connected mask suction unit 20a (that is, another mask suction unit 20a connected in the direction away from the negative pressure source 30) and the negative pressure source 30 through the mask suction unit side hole portion 20k formed to penetrate in the Y-axis direction to form a suction path 20f (see FIG. 6). Note that the mask suction unit 20a1 is arranged at the position closest to the negative pressure source 30 when the mask suction portion 20 is composed of each of two mask suction units 20a, and is arranged at a position other than the end farthest from the negative pressure source 30 when the mask suction portion 20 is composed of each of three or more mask suction units 20a.

[0024] 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 is provided with a suction hole 20b for adsorbing the lower surface of the mask 13. The suction hole 20b extends in the -Z-axis direction and communicates with the mask suction unit side hole portion 20k formed along a direction substantially parallel to the contact surface 20d. The mask suction unit side hole portion 20k in the mask suction unit 20a2 is formed to penetrate the mask suction unit 20a2 in the Y-axis direction. The suction hole 20b is connected to the negative pressure source 30 through the suction pipe 20c and the mask suction unit side hole portion 20k. When the negative pressure source 30 is driven, the inside of the suction pipe 20c becomes negative pressure, and the lower surface of the mask 13 located above or in contact with the contact surface 20d is adsorbed.

[0025] When the mask suction unit 20a2 is arranged at the position closest to the negative pressure source 30, the through-hole formed by the mask suction unit side hole portion 20k functions as a suction path 20f to which the suction pipe 20c is connected to enable suction (adsorption) at the suction hole 20b. Further, when the mask suction unit 20 is constituted by each of the two mask suction units 20a, the through-hole formed by the mask suction unit side hole portion 20k is arranged at the position farthest from the negative pressure source 30 and is spatially connected to the through-hole of the mask suction unit side hole portion 20k of the mask suction unit 20a connected to the front side (that is, the negative pressure source 30 side).

[0026] As shown in FIG. 6, the mask suction unit 20a3 has a contact surface 20d that contacts the lower surface of the mask 13, is formed along a substantially parallel direction of the contact surface 20d, and communicates with a mask suction unit side hole portion 20k that penetrates the mask suction unit 20a3 in the Y-axis direction.

[0027] When the mask suction unit 20a3 is arranged at the position closest to the negative pressure source 30, one of the two through holes formed by the mask suction unit side hole portion 20k (that is, the through hole located on the Y-axis direction side in FIG. 6) is connected to the suction pipe 20c and functions as the suction path 20f. Further, when the mask suction portion 20 is composed of two or more mask suction units 20a, the other through hole of the two through holes formed by the mask suction unit side hole portion 20k (that is, the through hole located on the -Y-axis direction side in FIG. 6) is connected to the mask suction unit side hole portion 20k of the next-connected mask suction unit 20a (that is, another mask suction unit 20a connected in the direction away from the negative pressure source 30) and the negative pressure source 30 are spatially connected by the mask suction unit side hole portion 20k formed to penetrate in the Y-axis direction, and are connected to the mask suction unit side hole portions 20k of the other mask suction units 20a1, 20a2 to form the suction path 20f (see FIG. 6). Note that the mask suction unit 20a3 is arranged at the position closest to the negative pressure source 30 when the mask suction portion 20 is composed of each of two mask suction units 20a, and is arranged at a position other than the end position farthest from the negative pressure source 30 when the mask suction portion 20 is composed of each of three or more mask suction units 20a.

[0028] As described above, the mask suction part 20 is constituted by one or more mask suction units 20a (specifically, mask suction units 20a1, 20a2, 20a3). The mask suction part 20 can more easily adjust the suction force by being constituted by combining each of the three types of mask suction units 20a1, 20a2, 20a3 described above. The mask suction part 20 should enhance the adhesion of the mask 13 to the substrate 11 (that is, should suction more strongly) at a position such as a part where the density or number of the pattern holes 13a is large (that is, a part where the warp of the substrate 11 is likely to increase due to the reflow process). By arranging the mask suction units 20a1, 20a2 having suction holes 20b at such a position, the suction force can be further improved. Therefore, the screen printing apparatus 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 more correct the warp of the substrate 11 by the mask 13.

[0029] Note that the mask suction part 20 may branch the suction pipe 20c connected to the mask suction unit 20a and also connect it to the substrate clamp member 8a of the substrate clamp mechanism 8. That is, the screen printing apparatus 1 suctions the lower surface of the mask 13 using the mask suction part 20 and the substrate clamp member 8a by the same negative pressure source 30. Thereby, the screen printing apparatus 1 can increase the force pressing the substrate 11 in the -Z axis direction by the adsorbed mask 13 compared with the case where the lower surface of the mask 13 is suctioned using either one of the mask suction part 20 or the substrate clamp member 8a by suctioning the lower surface of the mask 13 using the mask suction part 20 and the substrate clamp member 8a. Therefore, the screen printing apparatus 1 can more correct the warp of the substrate 11 by the mask 13 by increasing the force pressing the substrate 11 in the -Z axis direction.

[0030] The lower receiving member 12 provided on the upper surface of the second base plate 10 is lifted up and down in the vertical direction (Z-axis direction, -Z-axis direction) by the drive of the lower receiving member lifting mechanism 9, and approaches or separates from the substrate 11 held by the substrate transfer mechanism 7. The lower receiving member 12 supports the lower surface of the substrate 11 from below by contacting the lower surface of the substrate 11.

[0031] The mask suction portion 20 is provided on the upper surface of the second base plate 10, and is lifted up and down in the vertical direction (Z-axis direction, -Z-axis direction) by the drive of the lower receiving member lifting mechanism 9 in the same manner as the lower receiving member 12, and approaches or separates from the substrate 11 held by the substrate transfer mechanism 7. Note that the contact surface 20d of the mask suction portion 20 does not contact the lower surface of the substrate 11 at the height (height H2 shown in FIG. 9) where the lower receiving member 12 contacts the lower surface of the substrate 11 (details will be described later).

[0032] The substrate clamping mechanism 8 is disposed above the substrate transfer mechanism 7. The substrate clamping mechanism 8 includes a pair of substrate clamping members 8a facing each other in the X-axis direction. By advancing and retracting either one of the substrate clamping members 8a in the Y-axis direction or -Y-axis direction, a pair of opposite sides of the substrate 11 (that is, each of a pair of opposite sides along the X-axis direction) are clamped and held fixed by the pair of substrate clamping members 8a. Further, as shown in FIG. 2B, each of the pair of substrate clamping members 8a has a plurality of suction holes 8c for sucking the mask 13 on the upper surface. Each of the plurality of suction holes 8c is provided along a pair of opposite sides of the substrate 11 (that is, the X-axis direction). Note that the negative pressure source connected to each of the plurality of suction holes 8c may be the negative pressure source 30 connected to the mask suction portion 20, or another negative pressure source (not shown).

[0033] In addition, when the negative pressure source connected to each of the plurality of suction holes 8c is the 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 is connected to the substrate clamping member 8a of a pair of substrate clamping mechanisms 8 described later. Thereby, the screen printing apparatus 1 can achieve suction of the lower surface of the mask 13 using the mask suction unit 20 and the substrate clamping member 8a by one negative pressure source 30.

[0034] 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 suction unit 20 and each of the suction holes 8c of the substrate clamping member 8a. Thereby, the screen printing apparatus 1 can suck the lower surface of the mask 13 from four directions (in the X-axis direction, -X-axis direction, Y-axis direction, and -Y-axis direction respectively) with respect to the substrate 11 using the mask suction unit 20 and the substrate clamping member 8a by one negative pressure source 30. Therefore, even if the substrate 11 is warped in any direction, it can be corrected more effectively. Accordingly, the screen printing apparatus 1 can increase the force pressing the substrate 11 in the -Z-axis direction by the adsorbed mask 13 as compared with the case where the lower surface of the mask 13 is sucked using either one of the mask suction unit 20 or the substrate clamping member 8a. That is, the screen printing apparatus 1 can correct the warp of the substrate 11 by the mask 13 more effectively by increasing the force pressing the substrate 11 in the -Z-axis direction.

[0035] The screen printing apparatus 1 holds the side edges of the substrate 11 from the Y-axis direction and the -Y-axis direction by the substrate clamping member 8a, and drives the substrate holding stage moving mechanism 2 while restricting the movement of the substrate 11 to raise the substrate 11 in the Z-axis direction. The screen printing apparatus 1 drives the substrate holding stage moving mechanism 2 to position it at a height where the upper surface of the substrate 11 contacts the lower surface of the mask 13. In this way, the screen printing apparatus 1 raises the substrate holding stage moving mechanism 2 in the Z-axis direction while holding the substrate 11 by the substrate clamping member 8a on the substrate holding stage 4, approaches the substrate 11 from below the mask 13, and positions it at a predetermined height where the upper surface of the substrate 11 contacts the lower surface of the mask 13.

[0036] 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 clamping member 8a. The mask suction portion 20 is positioned at a predetermined height where the contact surface 20d contacts the lower surface of the mask 13, or at a predetermined height (height H0 shown in FIG. 9) where the mask suction portion 20 can suction the lower surface of the mask 13 (that is, the mask suction portion 20 can suction the lower surface of the mask 13 by driving the negative pressure source 30) and the contact surface 20d does not contact the lower surface of the mask 13.

[0037] Next, the screen printing unit 3 will be described. In the examples shown in FIGS. 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 FIG. 2A). The frame body 14 is fixed at a predetermined height above the substrate holding stage moving mechanism 2, is disposed on the outer edge of the mask 13, and extends and holds the mask 13 at a predetermined height. The mask 13 is formed with a plurality of pattern holes 13a (see FIG. 2A), each corresponding to the shape and position of each of the plurality of electrodes 11a formed on the substrate 11 (see FIG. 2B).

[0038] The mask 13 has a squeegee head 15 disposed above it. The squeegee head 15 includes a horizontally formed plate 15a and a squeegee lifting mechanism 15c for lifting and lowering each of a plurality of squeegees 15b on the plate 15a. The squeegee lifting mechanism 15c has each of a plurality of rods 15d extending downward (in the -Z axis direction). Each of the plurality of rods 15d has a squeegee 15b attached to its lower end. Each of the plurality of squeegees 15b is driven by the squeegee lifting mechanism 15c configured integrally via the rod 15d and lowered to a height in contact with the upper surface of the mask 13 to print solder paste on the substrate 11.

[0039] Next, with reference to FIG. 3, the positional relationships among the mask suction part 20, the lower receiving member 12, and the substrate 11 will be described. FIG. 3 is a partial side view of the screen printing apparatus 1 according to the embodiment.

[0040] FIG. 3(a) is a diagram showing the positional relationship between the mask suction part 20 and the lower receiving member 12 or the substrate 11 when the dimension α1 in the conveyance direction (X-axis direction) of the substrate 11 is less than or equal to the dimension β1 in the X-axis direction of the lower receiving member 12 (that is, dimension α1 ≤ dimension β1). Each of the plurality of mask suction parts 20 is disposed at a position separated by a predetermined distance from the lower receiving member 12 in each of the X-axis direction and the -X-axis direction with the lower receiving member 12 disposed on the upper surface of the second base plate 10 sandwiched therebetween.

[0041] FIG. 3(b) is a diagram showing the positional relationship between the mask suction part 20 and the lower receiving member 12 or the substrate 11 when the dimension α2 in the conveyance direction (X-axis direction) of the substrate 11 is greater than the dimension β2 in the X-axis direction of the lower receiving member 12 (that is, dimension α2 > dimension β2). Each of the plurality of mask suction parts 20 is disposed at a position separated by a predetermined distance from the lower receiving member 12 in each of the X-axis direction and the -X-axis direction with the lower receiving member 12 disposed on the upper surface of the second base plate 10 sandwiched therebetween.

[0042] Next, the arrangement of each of the pair of mask suction portions 20 will be described here. 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 suction unit 20a of each of the pair of mask suction portions 20 arranged in the -X-axis direction and the X-axis direction of the lower receiving member 12, respectively. Each of the plurality of mask suction portions 20 is arranged such that when dimension α1 ≤ dimension β1, distance γ1 > dimension β1, and when dimension α2 > dimension β2, distance γ2 > dimension α2 > dimension β2. Thereby, even when the dimension of the substrate 11 is larger than the dimension of the lower receiving member (that is, dimension α2 > dimension β2), the mask 13 can adsorb the entire upper surface of the substrate 11 in a covered state. Also, thereby, each of the plurality of mask suction portions 20 can avoid interference between the mask suction portion 20 and the substrate 11 even when it is lifted to substantially the same height as the substrate 11 by the substrate holding stage moving mechanism 2 and the lower receiving member elevating mechanism 9, respectively.

[0043] Note that, although an example is shown in which each of the pair of mask suction portions 20 shown in FIG. 3 is arranged at a position separated from the lower receiving member 12 by a predetermined distance equal in the X-axis direction and the -X-axis direction, respectively, the present invention is not limited thereto. Each of the pair of mask suction portions 20 may be arranged at a position separated from the lower receiving member 12 by an arbitrary distance that is different for each based on the number and position of each of the plurality of pattern holes 13a formed in the mask 13. Thereby, the screen printing apparatus 1 can adjust the suction strength according to the pattern holes 13a formed in each of the masks 13.

[0044] Next, with reference to FIGS. 4A to 4G, a configuration example of each of a plurality of mask suction units 20a that constitute a mask suction portion 20 disposed on a second base plate 10 (see FIGS. 1 and 2) will be described. FIG. 4A is a diagram showing a first configuration example of the mask suction portion 20 in the embodiment. FIG. 4B is a diagram showing a second configuration example of the mask suction portion 20 in the embodiment. FIG. 4C is a diagram showing a third configuration example of the mask suction portion 20 in the embodiment. FIG. 4D is a diagram showing a fourth configuration example of the mask suction portion 20 in the embodiment. FIG. 4E is a diagram showing a fifth configuration example of the mask suction portion 20 in the embodiment. FIG. 4F is a diagram showing a sixth configuration example of the mask suction portion 20 in the embodiment. FIG. 4G is a diagram showing a seventh configuration example of the mask suction portion 20 in the embodiment. Needless to say, the configuration of the mask suction portion 20 is not limited to each configuration example shown in FIGS. 4A to 4G.

[0045] Each of the pair of mask suction portions 20 is disposed between each of the pair of substrate transfer mechanisms 7 and in each of the X-axis direction and the -X-axis direction (that is, the left side and the right side of the paper surface) of the substrate 11. Each of the pair of mask suction portions 20 is raised in the Z-axis direction by a substrate holding stage moving mechanism 2 to a predetermined height at which the lower surface of the mask 13 contacts the contact surface 20d of the mask suction portion 20, or is positioned at a predetermined height at which the mask suction portion 20 can suck the lower surface of the mask 13 by driving a negative pressure source 30. After raising each of the pair of mask suction portions 20 to a predetermined height, the screen printing apparatus 1 drives the negative pressure source 30 and sucks the lower surface of the mask 13 from directions corresponding to each of the four sides of the mask 13 formed in a substantially rectangular shape by each of the pair of mask suction portions 20 and each of the pair of substrate clamping mechanisms 8.

[0046] Each of the pair of mask suction portions 20 is configured to include at least one mask suction unit 20a. Further, at least one mask suction unit 20a constituting each of the pair of mask suction portions 20 includes at least one suction hole 20b.

[0047] The mask suction unit 20a is provided with a suction passage 20f (see FIGS. 6 and 7) for transmitting at least the negative pressure generated by driving the negative pressure source 30 to the suction holes 20b. The suction passage 20f is provided along a direction parallel to the contact surface 20d. Note that when the mask suction part 20 is constituted by each of a plurality of mask suction units 20a, the suction holes 20b do not necessarily have to be provided in each of all the mask suction units 20a, and it is sufficient if the suction holes 20b are provided in at least one mask suction unit 20a.

[0048] The pair of mask suction parts 20 shown in FIG. 4A shows an example integrally constituted by connecting (coupling) each of the four mask suction units 20a having the suction holes 20b to the contact surface 20d. The pair of mask suction parts 20 sucks the lower surface of the mask 13 in a suction region 20e (a region indicated by a broken line shown around the suction hole 20b) including the vicinity of the suction holes 20b each mask suction unit 20a has. Here, the suction region 20e includes at least the suction holes 20b, and is a region capable of sucking the lower surface of the mask 13 by transmitting the negative pressure generated by driving the negative pressure source 30 to the suction holes 20b through the suction passage 20f communicating with the suction pipe 20c.

[0049] The pair of mask suction parts 20 shown in FIG. 4B shows an example integrally constituted by connecting (coupling) each of the six mask suction units 20a having the suction holes 20b to the contact surface 20d. The pair of mask suction parts 20 sucks the lower surface of the mask 13 in a suction region 20e (a region indicated by a broken line shown around the suction hole 20b) including the vicinity of the suction holes 20b each mask suction unit 20a has.

[0050] Each of FIGS. 4A and 4B is a diagram showing an example in which the number of mask suction units 20a constituting the mask suction portion 20 is changed in accordance with the dimension of the substrate 11 in the Y-axis direction, and the arrangement position of the mask suction portion 20 in the X-axis direction (that is, the distance between the substrate 11 and the mask suction portion 20) is changed. 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. Thereby, even when the operator prints solder on a substrate 11 whose dimensions (size) have changed due to heat treatment such as a reflow process, or a substrate 11 having different dimensions (size), etc., the number of mask suction units 20a constituting the mask suction portion 20, and the arrangement position of the mask suction portion 20 (that is, the distance between the substrate 11 and the mask suction portion 20) can be adjusted to more appropriately adsorb the mask 13.

[0051] Specifically, when the operator prints solder on a substrate 11 having a smaller dimension, the number of mask suction units 20a constituting the mask suction portion 20 is reduced, and the distance between each of the pair of mask suction portions 20 and the substrate 11 is adjusted. On the other hand, when the operator prints solder on a substrate 11 having a larger dimension, the number of mask suction units 20a constituting the mask suction portion 20 is increased, and the distance between each of the pair of mask suction portions 20 and the substrate 11 is adjusted.

[0052] Note that even when the screen printing apparatus 1 prints solder on a substrate 11 having a dimension (size) different from the dimension of the substrate 11 before the reflow process, if it is possible to achieve the adhesion between the upper surface of the substrate 11 and the lower surface of the mask 13 with the number and arrangement position of each of the pair of mask suction portions 20 installed at the time of the solder printing process on the substrate 11 before the reflow process, the number and arrangement position of the mask suction units 20a by the operator do not have to be adjusted (changed), or only one of them may be adjusted (changed).

[0053] Each of the pair of mask suction portions 20 shown in FIG. 4C shows an example composed of each of three mask suction units 20a having suction holes 20b provided in the contact surface 20d and each of two mask suction units 20a having no suction holes 20b provided in the contact surface 20d. Each of the pair of mask suction units 20a only needs to have a suction hole 20b in at least one of the plurality of mask suction units 20a. Among the plurality of mask suction units 20a constituting the mask suction portion 20, by increasing or decreasing the number of mask suction units 20a (specifically, mask suction units 20a1, 20a2) in which the suction hole 20b is not provided or adjusting the arrangement, and changing the suction region 20e, the suction force (suction) of the mask suction portion 20 with respect to the lower surface of the mask 13 can be adjusted.

[0054] Each of the pair of mask suction portions 20 shown in FIG. 4D shows an example in which the mask suction units 20a constituting the mask suction portion 20 are different. For example, the mask suction portion 20 installed in the -X axis direction with respect to the substrate 11 is composed of each of three mask suction units 20a having suction holes 20b provided in three contact surfaces 20d and each of one mask suction unit 20a having no suction holes 20b provided in the contact surface 20d, and suction pipes 20c are connected to two of these four mask suction units 20a.

[0055] Also, for example, the mask suction portion 20 installed in the X axis direction with respect to the substrate 11 is composed of each of three mask suction units 20a having suction holes 20b provided in three contact surfaces 20d and each of two mask suction units 20a having no suction holes 20b provided in the contact surface 20d, and a suction pipe 20c is connected to one of these five mask suction units 20a. Thereby, each of the pair of mask suction portions 20 adjusts the suction force (suction) of the mask suction portion 20 with respect to the lower surface of the mask 13 and the area of the suction region 20e according to the size, arrangement, etc. of the pattern holes 13a formed in the mask 13, and can more appropriately adsorb the lower surface of the mask 13.

[0056] Each of the pair of mask suction portions 20 shown in FIG. 4E is constituted by each of three mask suction units 20a provided with suction holes 20b in the contact surface 20d and connected with suction pipes 20c. Each of the mask suction units 20a can individually suction the lower surface of the mask 13 by the suction holes 20b, and is arranged at equal intervals along the Y-axis direction, and the suction holes 20b provided in the contact surface 20d communicate with the mask suction unit side hole portions 20k and the suction paths 20f (see FIG. 6). Each of the mask suction units 20a has the suction path 20f connected with the suction pipe 20c, and suctions the lower surface of the mask 13 located on the contact surface 20d by driving of a negative pressure source 30 connected with the suction pipe 20c.

[0057] Each of the pair of mask suction portions 20 shown in FIG. 4F is constituted by each of two mask suction units 20a provided with suction holes 20b in the contact surface 20d and connected with suction pipes 20c. Each of the mask suction units 20a can individually suction the lower surface of the mask 13 by the suction holes 20b, and is arranged at equal intervals in the Y-axis direction, and the suction holes 20b provided in the contact surface 20d communicate with the mask suction unit side hole portions 20k and the suction paths 20f (see FIG. 6). Each of the mask suction units 20a has the suction path 20f connected with the suction pipe 20c, and suctions the lower surface of the mask 13 located on the contact surface 20d by driving of a negative pressure source 30 connected with the suction pipe 20c.

[0058] Note that the number of mask suction units 20a constituting the pair of mask suction portions 20 shown in FIG. 4E is larger than the number of mask suction units 20a constituting the pair of mask suction portions 20 shown in FIG. 4F. The closer the arrangement interval of the mask suction units 20a having the suction holes 20b in the mask suction portion 20 is, the more the suction force for suctioning the lower surface of the mask 13 is improved. Therefore, for example, when the substrates 11 shown in FIGS. 4E and 4F respectively have the same dimensions, the suction force of the pair of mask suction portions 20 shown in FIG. 4E is larger than the suction force of the pair of mask suction portions 20 shown in FIG. 4F.

[0059] Each of the pair of mask suction parts 20 shown in Fig. 4G is constituted by each of four mask suction units 20a provided with suction holes 20b in the contact surface 20d and to which suction pipes 20c are connected. Each of the mask suction units 20a can individually adsorb the lower surface of the mask 13 by the suction holes 20b, is arranged at equal intervals along the Y-axis direction, and the suction holes 20b provided in the contact surface 20d communicate with the mask suction unit side hole parts 20k and the suction paths 20f (see Fig. 6). Each of the mask suction units 20a has the suction path 20f connected to the suction pipe 20c, and adsorbs the lower surface of the mask 13 positioned on the contact surface 20d by the drive of the negative pressure source 30 connected to the suction pipe 20c.

[0060] Note that the number of mask suction units 20a constituting the pair of mask suction parts 20 shown in Fig. 4E is smaller than the number of mask suction units 20a constituting the pair of mask suction parts 20 shown in Fig. 4G. Therefore, for example, when the substrates 11 shown in Figs. 4E and 4G have the same dimensions, the adsorption force of the pair of mask suction parts 20 shown in Fig. 4E is smaller than the adsorption force of the pair of mask suction parts 20 shown in Fig. 4G.

[0061] As described above, the adsorption area 20e and the adsorption force of the mask suction part 20 can be adjusted based on the number or arrangement of the mask suction units 20a having the suction holes 20b (specifically, mask suction units 20a1 and 20a2). Note that the mask suction part 20 does not have to have its type, number, or arrangement of the mask suction units 20a adjusted for each dimension of the substrate 11. For example, even when printing solder paste on substrates 11 of different dimensions, if sufficient adhesion between the upper surface of the substrate 11 and the lower surface of the mask 13 required for the printing process can be obtained, the mask suction part 20 may be used as it is without adjusting the type, number, or arrangement of the mask suction units 20a.

[0062] Note that the mask suction parts 20 shown in FIGS. 4A to 4C and FIGS. 4E to 4G have been described for the case where 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, for example, it is not necessary for all the mask suction units 20a to be arranged at equal intervals as in the mask suction part 20 shown in FIG. 4D. Further, for example, as in the pair of mask suction parts 20 shown in FIG. 4D, the types, numbers, or arrangements of the mask suction units 20a that constitute each of the pair of mask suction parts 20 do not have to be the same. Thereby, the operator can more easily adjust the configuration of the mask suction part 20 so that sufficient adhesion between the upper surface of the substrate 11 and the lower surface of the mask 13 necessary for printing the solder paste is obtained based on the dimensions of the substrate 11 or the pattern holes 13a of the mask 13.

[0063] FIG. 5 is a perspective view of the mask suction part 20 shown in FIGS. 4C and 4E. FIG. 5(a) shows a perspective view of the mask suction part 20 shown in FIG. 4C. FIG. 5(b) shows a perspective view of the mask suction part 20 shown in FIG. 4E.

[0064] The mask suction part 20 shown in FIG. 5(a) is integrally configured by coupling each of a plurality of mask suction units 20a to each other. Specifically, the mask suction part 20 shown in FIG. 5(a) is configured by coupling the mask suction unit 20a1, the mask suction unit 20a3, the mask suction unit 20a1, the mask suction unit 20a3, and the mask suction unit 20a2 in this order in the -Y-axis direction (from the back to the front of the paper surface).

[0065] The mask suction unit leg part 20h is arranged on a second base plate 10 (not shown). The mask suction unit leg part 20h is connected to the mask suction unit 20a by a mask suction unit support part 20i that extends from above the mask suction unit leg part 20h, and supports the mask suction unit 20a.

[0066] The mask suction part 20 has a suction tube 20c connected to a mask suction unit side hole 20k (see FIG. 6) of a mask suction unit 20a1 arranged at the deepest part in the paper surface direction in the Y-axis direction among each of the plurality of mask suction units 20a. The mask suction part 20 forms a suction path 20f by connecting a suction hole 20b of each mask suction unit 20a and a negative pressure source 30 through the mask suction unit side hole 20k (see FIG. 6) formed inside each mask suction unit 20a, and sucks the lower surface of the mask 13 by driving the negative pressure source 30. Note that the suction tube 20c does not necessarily have to be connected to the mask suction unit 20a arranged at the deepest part as shown in FIG. 5(a), and may be connected to any one of the plurality of mask suction units 20a constituting the mask suction part 20. Also, the mask suction unit 20a to which the suction tube 20c is connected is not limited to any one of the plurality of mask suction units 20a, and may be connected to each of two or more mask suction units 20a.

[0067] The mask suction part 20 shown in FIG. 5(b) is composed of each of the mask suction units 20a that are not joined to each other and are independent. Specifically, the mask suction part 20 shown in FIG. 5(a) is composed of each of three mask suction units 20a2 that are not joined to each other.

[0068] The suction tube 20c is connected to a suction path 20f (see FIGS. 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 sucks the lower surface of the mask 13 by driving the negative pressure source 30. The mask suction unit 20a2 has an internally formed suction path 20f connected to the negative pressure source 30 via the suction tube 20c, and the negative pressure source 30 communicates with the suction tube 20c through the mask suction unit side hole 20k to suck the lower surface of the mask 13.

[0069] Next, referring to FIGS. 6 and 7, the suction path of the mask suction portion 20 shown in FIGS. 4C and 4E will be described. FIG. 6 is an S-S cross-sectional view of the mask suction portion 20 shown in FIG. 5. FIG. 7 is a T-T cross-sectional view of the mask suction portion 20 shown in FIG. 5. Here, the suction path refers to the path from each of the suction holes 20b of each mask suction unit 20a to the negative pressure source 30.

[0070] 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 shown only in some of the mask suction units 20a, and the illustration is omitted for the other mask suction units 20a.

[0071] The side hole 20r is provided to communicate with a threaded hole 20s into which the mask suction unit support portion 20i is screwed from the side surface of the mask suction unit 20a. The side hole 20r includes a fixing member 20m for fixing the screwed state of the mask suction unit support portion 20i. The fixing member 20m is, for example, a set screw with a hexagonal hole or the like, and by pressing the mask suction unit support portion 20i screwed into the threaded hole 20s in the Y-axis direction, 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 portion 20i is suppressed. Note that the fixing member 20m is not limited to the above-described set screw with a hexagonal hole or the like, and any member that can press the mask suction unit support portion 20i may be used.

[0072] The mask suction unit support part 20i has male threads at both the upper and lower parts, and is screwed into a threaded hole 20s formed on the lower surface (the surface in the -Z axis direction) of the mask suction unit 20a and a threaded hole 20t formed on the upper surface of the mask suction unit leg part 20h facing the lower surface of the mask suction unit 20a. The mask suction unit support part 20i is rotated in a predetermined direction by an operator to enable adjustment of the Z-axis height of the contact surface 20d and the suction holes 20b of the mask suction unit 20a. Note that the mask suction unit support part 20i may be adhered and fixed to the threaded hole 20s. In such a case, the side hole 20r and the fixing member 20m become unnecessary. Also, the upper part of the mask suction unit support part 20i does not need to have a male thread formed thereon.

[0073] Note that the elevating means in the Z-axis direction of the mask suction unit 20a is not limited to the mask suction unit support part 20i. For example, the mask suction unit 20a may be provided with an elevating means such as a cylinder below the mask suction unit 20a to achieve elevation and descent in the Z-axis direction.

[0074] Also, the mask suction unit 20a is coupled to other mask suction units 20a by the convex part 20о and the concave part 20p described later. If the bonding force due to the coupling of the convex part 20о and the concave part 20p, or the balance degree of the contact surface 20d with respect to the lower surface of the mask 13, etc. is sufficient for the suction of the lower surface of the mask 13, the configurations of the mask suction unit leg part 20h and the mask suction unit support part 20i may be omitted.

[0075] The leg portion 20h of the mask suction unit houses a magnet member 20j that can fix the mask suction unit 20a, with a leg-side hole portion 20l formed in the surface that contacts the second base plate 10, which is the installation surface of the mask suction unit 20a, in the direction toward the inside of the leg portion 20h of the mask suction unit (for example, the Z-axis direction shown in FIG. 6). Note that the magnet member 20j may not be housed in the leg-side hole portion 20l and may be coupled to the lower surface of the leg portion 20h of the mask suction unit. In such a case, the magnet member 20j may be formed to have the same size and shape as the lower surface of the leg portion 20h of the mask suction unit. Also, the height of the magnet member 20j may be the same as the depth of the hole of the leg-side hole portion 20l or may be smaller than the depth of the hole of the leg-side hole portion 20l. Thereby, an operator can more easily attach and detach the mask suction unit 20a onto the second base plate 10 or adjust the positions of the respective one or more mask suction units 20a that constitute the mask suction portion 20 by the magnet member 20j on the lower surface of the leg portion 20h of the mask suction unit.

[0076] In the mask suction portion 20 shown in FIG. 6, the mask suction unit-side hole portion 20k of the mask suction unit 20a1 to which the suction pipe 20c is connected, the mask suction unit-side hole portion 20k of another mask suction unit 20a connected to the mask suction unit-side hole portion 20k, and the suction holes 20b function as a suction path for sucking the mask 13. Thereby, the mask suction portion 20 can suck the lower surface of the mask 13 by driving the negative pressure source 30.

[0077] The mask suction portion 20 shown in FIG. 7 sucks the lower surface of the mask 13 through the respective suction holes 20b of these three mask suction units 20a2. Note that the negative pressure sources 30 connected to the respective three mask suction units 20a2 may be the same negative pressure source 30 or may be different negative pressure sources (not shown).

[0078] Next, with reference to FIG. 8, a structure for coupling each of the plurality of mask suction units 20a will be described. FIG. 8 is a diagram for explaining an example of coupling the mask suction units 20a in the embodiment.

[0079] FIG. 8(a) is a diagram showing a joint surface 20n where the mask suction units 20a are joined together. In the central portion of the joint surface 20n, a through-hole of a mask suction unit side hole portion 20k formed toward the inside of the mask suction unit 20a penetrates, and a convex portion 20o and a concave portion 20p are respectively formed around the mask suction unit side hole portion 20k. Note that the number and positions of the convex portion 20o and the concave portion 20p shown in FIG. 8 are examples and may not be limited thereto.

[0080] Each of the convex portions 20o is provided at a position that can be fitted into each of the concave portions 20p formed in the other mask suction unit 20a as shown in FIG. 8(b). Each of the convex portions 20o fits into each of the concave portions 20p formed in the other mask suction unit 20a to join the respective two mask suction units 20a.

[0081] Each of the concave portions 20p is a depression provided toward the inside of the mask suction unit 20a, and is provided at a position that can be fitted into each of the convex portions 20о formed in the other mask suction unit 20a as shown in FIG. 8(b).

[0082] Note that the shapes of the convex portion 20o and the concave portion 20p are not limited to the spherical shapes shown in FIG. 8, and may be, for example, columnar, quadrangular columnar, triangular pyramid-shaped, conical, or the like. Also, in order to prevent incorrect joining of the mask suction units 20a (for example, joining in a state where the suction hole 20b faces the second base plate 10 side, joining in a state where the mask suction unit side hole portions 20k of the mask suction units 20a are not connected, etc.), as shown in FIG. 8, two convex portions 20o or concave portions 20p are arranged at the upper part of the joint surface 20n, and one convex portion 20o or concave portion 20p is formed at the lower part of the joint surface 20n, so that the joining direction of the mask suction units 20a can be limited. Therefore, the mask suction unit 20a in the present embodiment can more effectively prevent incorrect joining of the mask suction units 20a by having different numbers of convex portions 20o and concave portions 20p at the upper and lower (or left and right) parts of the joint surface 20n.

[0083] Further, the convex portion 20o formed on one of the opposing joint surfaces 20n may be formed of a magnetic material. In such a case, an operator can utilize the magnetic force by which the concave portion 20p formed on the other joint surface 20n is attracted toward the convex portion 20o to join the mask suction units 20a to each other, so that joining and separation can be performed more easily.

[0084] FIG. 8(b) is a diagram showing the height relationship between the convex portion 20о and the concave portion 20p formed on each of the joint surfaces 20n of the two mask suction units 20a. Each of the convex portion 20о and the concave portion 20p is formed to have a height that can be fitted to each other.

[0085] FIG. 8(c) is a diagram showing the state of joining of each of the two mask suction units 20a. Each of the two mask suction units 20a has the relative positions of their joint surfaces 20n fixed and positioned by fitting of the convex portion 20o and the concave portion 20p to each other. Thereby, each of the two mask suction units 20a joins the mask suction units 20a to each other without variation in the height of the contact surface 20d of the mask suction units 20a of each other.

[0086] With reference to FIGS. 9 and 10, the operation procedure until the mask suction portion 20 sucks the lower surface of the mask 13 will be described. FIG. 9 is a diagram for explaining an example of the suction operation of the mask suction portion 20 in the embodiment. FIG. 10 is a diagram for explaining an example of the suction operation of the mask suction portion 20 in the embodiment. Note that FIG. 9 is a side view of the screen printing apparatus 1 as viewed from the X-axis direction. FIG. 10 is a cross-sectional view showing the UU cross-section, VV cross-section, and WW cross-section of the screen printing apparatus 1 obtained by cutting the screen printing apparatus 1 along each of the cross-section lines shown in FIG. 9. Note that the screen printing apparatus 1 shown in FIGS. 9 and 10 shows the configuration necessary for explaining the operation procedure until the mask suction portion 20 sucks the lower surface of the mask 13, and illustration of some configurations is omitted.

[0087] As shown in FIGS. 9(a) and 10(a), in the screen printing apparatus 1, a substrate 11 carried in from the upstream side is conveyed to a predetermined substrate conveyance position by a substrate conveyance conveyor 7a of a substrate conveyance mechanism 7, and is shown in a state of being positioned above a receiving member 12 by a substrate holding stage moving mechanism 2.

[0088] As shown in FIGS. 9(a) and 10(a), after the substrate 11 is positioned above the receiving member 12 by the substrate holding stage moving mechanism 2, as shown in FIGS. 9(b) and 10(b), a receiving member elevating mechanism 9 is driven. The screen printing apparatus 1 raises a second base plate 10 from a current height H1 to a height H2 at which the upper surface of the receiving member 12 abuts against the lower surface of the substrate 11 by the receiving member elevating mechanism 9. The receiving member 12 supports the lower surface of the substrate 11 from below at the position of the height H2.

[0089] Further, since the mask suction portion 20 is provided on the upper surface of the second base plate 10, it is raised in the Z-axis direction by the driving of the receiving member elevating mechanism 9. Note that the height of the mask suction unit leg portion 20h of the mask suction portion 20 may be adjusted so that the height of the contact surface 20d and the upper surface of the substrate 11 are the same at the height H2, or the height of the mask suction unit leg portion 20h may be adjusted so that the mask suction portion 20 can suction the lower surface of the mask 13 and the height of the contact surface 20d of the mask suction portion 20 after rising is below the height of the upper surface of the substrate 11 as shown in FIG. 9.

[0090] The screen printing apparatus 1 shown in FIGS. 9(c) and 10(c) drives the substrate holding stage moving mechanism 2 and raises the lower receiving member elevating mechanism 9 in the Z-axis direction. The screen printing apparatus 1 raises the lower receiving member elevating mechanism 9 from the current height H3 to the height H4 where the upper surface of the substrate 11 abuts the lower surface of the mask 13 while holding the substrate 11 at the height H0. Note that the height of the mask suction unit leg portion 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 at the height H2, or it may be adjusted to a height at which the lower surface of the mask 13 can be suctioned and, as shown in FIG. 9, the height of the contact surface 20d of the mask suction unit 20 after rising is lower than the height of the upper surface of the substrate 11.

[0091] After the screen printing apparatus 1 raises the lower receiving member elevating mechanism 9 from the current height H3 to the height H4 where the upper surface of the substrate 11 abuts the lower surface of the mask 13 by the substrate holding stage moving mechanism 2, it drives the negative pressure source 30 and suctions the lower surface of the mask 13 by the suction holes 8c of the substrate clamp mechanism 8 and the suction holes 20b of the mask suction unit 20. Thereby, the screen printing apparatus 1 according to the present embodiment can correct the warp of the substrate 11 more effectively even when the substrate 11 has a warp by suctioning the substantially rectangular mask 13 from four directions with respect to the substrate 11. Note that the screen printing apparatus 1 according to the present embodiment can correct the warp of the substrate 11 in the Y-axis direction more effectively by suctioning the lower surface of the mask 13 by a pair of mask suction units 20 arranged in the X-axis direction with the substrate 11 interposed therebetween even when the substrate 11 is warped along the direction orthogonal to the X-axis direction (that is, the Y-axis direction) in which the suction holes 8c are provided. Therefore, even when the substrate 11 has a warp, the screen printing apparatus 1 can improve the adhesion between the mask 13 and the substrate 11, so that the gap between the mask 13 and the substrate 11 can be made smaller. Thereby, the screen printing apparatus 1 suppresses the solder from being transferred to the lands on the substrate 11 in a state where the solder has entered the gap, and can more effectively suppress the occurrence of printing defects.

[0092] As described above, the screen printing apparatus 1 according to the embodiment includes a pair of substrate transfer conveyors 7a that transfer the substrate 11 to a predetermined position, a lower receiving member 12 that supports the substrate 11 at a predetermined position from below, a pair of substrate clamp members 8a that hold the opposing side edges of the substrate 11, a mask suction unit 20 that is disposed between the pair of substrate transfer conveyors 7a and suctions the mask 13 in a predetermined suction region 20e along a direction intersecting the side edges 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 the pattern holes 13a are formed and prints the paste onto the substrate 11 through the pattern holes 13a.

[0093] Accordingly, even when the substrate 11 is warped along the direction orthogonal to the X-axis direction (i.e., the Y-axis direction) in which the suction holes 8c are provided, the screen printing apparatus 1 according to the embodiment can correct the warp of the substrate 11 more by suctioning the mask 13 from four directions with respect to the substrate 11 (i.e., the opposing side edges (X-axis direction) of the substrate 11 and the direction orthogonal to these side edges (Y-axis direction)). Therefore, even if the substrate 11 is warped, the screen printing apparatus 1 can improve the adhesion between the mask 13 and the substrate 11, so that the gap between the mask 13 and the substrate 11 can be made smaller. As a result, the screen printing apparatus 1 can suppress the solder from being transferred to the lands on the substrate 11 in a state where the solder has entered the gap, and can more effectively suppress the occurrence of printing defects.

[0094] In addition, as described above, the mask adsorption unit 20 included in the screen printing apparatus 1 according to the embodiment has an adsorption region 20e based on the number or arrangement of at least one suction hole 20b (an example of the first suction hole) that contacts the mask 13 and can adsorb the mask 13. Thereby, the screen printing apparatus 1 according to the embodiment can adjust the adsorption region 20e based on the number or arrangement of the suction holes 20b. Therefore, for each of the pair of mask adsorption units 20 of the screen printing apparatus 1, the adsorption force (suction force) of the mask adsorption unit 20 with respect to the lower surface of the mask 13 and the area of the adsorption region 20e can be adjusted according to the size, arrangement, etc. of the pattern holes 13a formed in the mask 13, so that the lower surface of the mask 13 can be adsorbed more appropriately and the warp of the substrate 11 can be corrected more appropriately.

[0095] In addition, as described above, the mask adsorption unit 20 included in the screen printing apparatus 1 according to the embodiment is composed of at least one mask adsorption unit 20a and has at least one suction hole 20b on the contact surface 20d that contacts the mask 13. Thereby, the screen printing apparatus 1 according to the embodiment can suck and adsorb the lower surface of the mask 13.

[0096] In addition, as described above, each of the plurality of mask adsorption units 20a included in the screen printing apparatus 1 according to the embodiment is coupled to each other to form one mask adsorption unit 20, and at least one mask adsorption unit 20a is connected to the negative pressure source 30 to adsorb the mask 13. Thereby, the screen printing apparatus 1 according to the embodiment can adjust the magnitude of the adsorption force (suction force) of the mask adsorption unit 20 with respect to the lower surface of the mask 13 and the area of the adsorption region 20e according to the size of the substrate 11, the size or arrangement of the pattern holes 13a formed in the mask 13, etc., so that the lower surface of the mask 13 can be adsorbed more appropriately and the warp of the substrate 11 can be corrected more appropriately.

[0097] Further, as described above, the mask adsorption unit 20a included in the screen printing apparatus 1 according to the embodiment has a mask adsorption unit side hole portion 20k (an example of a space) along the contact surface 20d inside the mask adsorption unit 20a, and forms a suction path 20f that connects the suction holes 20b and the negative pressure source 30 by the mask adsorption unit side hole portion 20k. Thereby, even when the mask adsorption portion 20 of the screen printing apparatus 1 according to the embodiment includes each of the plurality of suction holes 20b, the mask 13 can be adsorbed (suctioned) by one negative pressure source 30.

[0098] Further, as described above, when the mask adsorption portion 20 included in the screen printing apparatus 1 according to the embodiment is configured by 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. Thereby, the screen printing apparatus 1 according to the embodiment can further improve the adsorption force (suction force) of the mask adsorption portion 20.

[0099] Further, as described above, the screen printing apparatus 1 according to the embodiment further includes a mask adsorption unit support portion 20i that moves the mask adsorption unit 20a up and down and a mask adsorption unit leg portion 20h (an example of a lifting portion). The mask adsorption unit support portion 20i and the mask adsorption unit leg portion 20h are arranged on the same surface as the installation surface of the lower receiving member 12 (that is, the upper surface of the second base plate 10). Thereby, the screen printing apparatus 1 according to the embodiment can adjust the height of the contact surface 20d and the suction holes 20b of the mask adsorption portion 20 to a height corresponding to the thickness of the substrate 11 or the like.

[0100] Further, as described above, the mask adsorption unit support portion 20i and the mask adsorption unit leg portion 20h included in the screen printing apparatus 1 according to the embodiment have a magnet member 20j (an example of a magnetic body) on the surface that contacts the installation surface where the lower receiving member 12 is installed (that is, the upper surface of the second base plate 10) (that is, the bottom surface of the mask adsorption unit leg portion 20h). Thereby, the operator can more easily change or adjust the configuration and arrangement of the mask adsorption portion 20.

[0101] Further, as described above, the screen printing apparatus 1 according to the embodiment is provided in each of the pair of substrate clamp members 8a, and further includes each of a plurality of suction holes 8c (an example of the second suction holes) that adsorb the substrate 11 along the side direction. The suction holes 20b of the mask suction portion 20 and the suction holes 8c of the substrate clamp member 8a are connected to the negative pressure source 30 to adsorb the mask 13. Thereby, 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 (each of the X-axis direction, -X-axis direction, Y-axis direction, and -Y-axis direction) using the mask suction portion 20 and the substrate clamp member 8a by one negative pressure source 30. Therefore, no matter in which direction the substrate 11 is warped, it can be corrected more effectively. Accordingly, the screen printing apparatus 1 can increase the force pressing the substrate 11 in the -Z-axis direction by the adsorbed mask 13 as compared with the case where the lower surface of the mask 13 is adsorbed using either one of the mask suction portion 20 or the substrate clamp member 8a. That is, the screen printing apparatus 1 can correct the warp of the substrate 11 by the mask 13 more effectively by increasing the force pressing the substrate 11 in the -Z-axis direction.

[0102] Further, as described above, the suction holes 20b of the mask suction portion 20 included 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. Thereby, the screen printing apparatus 1 according to the embodiment can adjust the magnitude of the adsorption force (suction force) of the mask suction portion 20 on the lower surface of the mask 13 and the area of the adsorption region 20e according to the size of the substrate 11, the size or arrangement of the pattern holes 13a formed in the mask 13, etc., can adsorb the lower surface of the mask 13 more appropriately, and can correct the warp of the substrate 11 more appropriately.

[0103] The various embodiments have been described above with reference to the accompanying drawings, but the present disclosure is not limited to such examples. It is obvious that those skilled in the art can conceive of various modification examples, correction examples, substitution examples, addition examples, deletion examples, and equivalent examples within the scope described in the claims, and it is understood that they also belong to the technical scope of the present disclosure. Further, within the scope not departing from the gist of the invention, the components in the above-described various embodiments may be arbitrarily combined.

Industrial Applicability

[0104] The present disclosure is useful as a screen printing apparatus that can more effectively correct the warp of a substrate, improve the adhesion between the substrate and the mask, and achieve high-quality printing.

Explanation of Signs

[0105] 1 Screen printing apparatus 2 Substrate holding stage moving mechanism 3 Screen printing section 4 Substrate holding stage 7 Substrate conveying mechanism 7a Substrate conveying conveyor 8 Substrate clamping mechanism 8a Substrate clamping member 8c Suction hole 11 Substrate 12 Lower receiving member 13 Mask 13a Pattern hole 20 Mask adsorption section 20a Mask adsorption unit 20b Suction hole 20d Contact surface 20e Adsorption region 20f Suction path 20k Mask adsorption unit side hole portion 20i Mask adsorption unit support portion 20j Magnet member 30 Negative pressure source

Claims

1. A pair of substrate transfer conveyors for transferring a substrate to a predetermined position, A lower receiving member for supporting the substrate at the predetermined position from below, A pair of substrate clamp members for holding the opposing side edges of the substrate, Composed of at least one mask suction unit, disposed between the pair of substrate transfer conveyors, and a mask suction portion for sucking a mask in a predetermined suction region along a direction intersecting the side edge by driving a negative pressure source, A printing portion for bringing the substrate into contact with the mask having pattern holes and printing paste onto the substrate through the pattern holes, A lifting portion for movably lifting the mask suction unit, and further comprising, The mask suction portion has at least one first suction hole on a contact surface that contacts the mask, The lifting portion is disposed on the same surface as the installation surface of the lower receiving member, A screen printing device.

2. A pair of substrate transfer conveyors for transferring a substrate to a predetermined position, A lower receiving member for supporting the substrate at the predetermined position from below, A pair of substrate clamp members for holding the opposing side edges of the substrate, Composed of at least one mask suction unit, disposed between the pair of substrate transfer conveyors, and a mask suction portion for sucking a mask in a predetermined suction region along a direction intersecting the side edge by driving a negative pressure source, A printing portion for bringing the substrate into contact with the mask having pattern holes and printing paste onto the substrate through the pattern holes, A lifting portion for movably lifting the mask suction unit, and further comprising, The mask suction portion has the suction region based on the number or arrangement of at least one first suction hole that contacts the mask and can suck the mask, The mask suction portion has at least one of the first suction holes on a contact surface that contacts the mask, The lifting portion is disposed on the same surface as the installation surface of the lower receiving member, A screen printing device.

3. Each of the plurality of mask suction units is coupled to each other to form one mask suction portion, and at least one of the mask suction units is connected to the negative pressure source to suck the mask, The screen printing device according to claim 1 or 2.

4. The mask suction unit has a space along the contact surface inside the mask suction unit, and the space forms a suction path connecting the first suction hole and the negative pressure source, The screen printing device according to claim 3.

5. When the mask suction part is composed of two or more of the mask suction units, each of the two or more mask suction units is individually connected to the negative pressure source to suck the mask. The screen printing apparatus according to claim 1 or 2.

6. The elevating part has a magnetic body on the surface that contacts the installation surface. The screen printing apparatus according to claim 5.

7. Further provided with a plurality of second suction holes provided in each of the pair of substrate clamping members and sucking the mask along the direction of the side. The first suction hole and the second suction hole are connected to the negative pressure source to suck the mask. The screen printing apparatus according to claim 2.

8. The first suction hole is arranged at a position corresponding to the position of the pattern hole of the mask. The screen printing apparatus according to claim 2.

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