JP7656845B2 - Work holding device and screen printing machine - Google Patents

Description

This disclosure relates to a workpiece holding device that clamps and holds both end surfaces of a workpiece such as a substrate, and a screen printing machine having this workpiece holding device.

Conventionally, there is known a screen printer that applies a paste such as solder to a substrate as a workpiece. The screen printer holds the substrate using a substrate holding mechanism. The screen printer then brings a mask plate into contact with the top surface of the held substrate. A squeegee is then slid over the mask plate to scrape up the paste on the mask plate, thereby applying the paste to the top surface of the substrate through the pattern holes provided in the mask plate. The substrate holding mechanism of such a screen printer has a push-up section that pushes up the substrate, and a pair of side clampers that laterally clamp both end faces of the substrate pushed up by the push-up section. This substrate holding mechanism brings the substrate, with both end faces clamped by the pair of side clampers, into contact with the mask plate.

Among the substrate holding mechanisms of such screen printers, there is one in which a pair of top clampers are provided at a predetermined protruding position above a pair of side clampers. The top surfaces of both ends of the pushed-up substrate come into contact with the top clampers from below (for example, see Patent Document 1). In a substrate holding mechanism configured in this way, the height of the bottom surface of the top clamper is set to the same height as the top surface of the side clampers, so that the substrate can be clamped in a state in which the height of the top surface of the pushed-up substrate is the same as the height of the top surface of the side clampers. This increases the degree of adhesion between the substrate and the mask plate when they are brought into contact, thereby improving the printing accuracy of the screen printer.

JP 2007-160692 A

However, in the conventional screen printing machine described above, the pair of top clampers are configured to extend from a storage position on the outside of the pair of side clampers (the side where the two top clampers move away from each other) to an extended position above the side clampers. This means that the path of movement of the top clampers between the storage position and the extended position is extremely long. This means that the mechanism for moving the top clampers becomes large, which may result in an increase in the overall size of the screen printing machine.

The present disclosure provides a workpiece holding device that can move the top clamper in a compact configuration and prevents the device from becoming too large overall, and a screen printing machine that includes this workpiece holding device.

A work holding device according to one aspect of the present disclosure includes a push-up section that pushes up a workpiece, a first side clamper and a second side clamper that clamp the workpiece pushed up by the push-up section at both opposing end surfaces of the workpiece, a side clamper drive section that causes the first and second side clampers to clamp both end surfaces of the workpiece, a first top clamper that is movable between a first storage position and a first protruding position above the first side clamper, a second top clamper that is movable between a second storage position and a second protruding position above the second side clamper, and a top clamper moving section that moves the first top clamper between the first storage position and the first protruding position and moves the second top clamper between the second storage position and the second protruding position, and a top clamper moving section that moves the first side .... A first storage space is provided on the upper surface side of the second side clamper to store the second top clamper positioned at the second storage position, and a second storage space is provided on the upper surface side of the second side clamper to store the second top clamper positioned at the second storage position, and the first top clamper is abutted from below by the upper surface of one of the two ends of the workpiece pushed up by the push-up unit at the first extension position, and the second top clamper is abutted from below by the upper surface of the other of the two ends of the workpiece pushed up by the push-up unit at the second extension position, and the top clamper moving unit has a lifting cylinder that moves the first and second top clampers via a parallel link mechanism, and a slide cylinder that moves the first and second top clampers toward each other or away from each other.

A screen printing machine according to one aspect of the present disclosure includes the above-mentioned workpiece holding device, a mask plate, and a squeegee. The mask plate is provided with pattern holes. The mask plate is configured to contact the upper surface of the workpiece clamped by a pair of side clampers of the workpiece holding device. The squeegee is configured to slide over the mask plate in contact with the upper surface of the workpiece, scraping up the paste on the mask plate, thereby applying the paste to the upper surface of the workpiece through the pattern holes.

According to the present disclosure, the top clamper can be moved in a compact configuration, preventing the device from becoming too large overall.

FIG. 1 is a plan view of a screen printing machine according to an embodiment of the present disclosure. FIG. 2 is a front view of the screen printing machine shown in FIG. FIG. 2 is a side view of the screen printing machine shown in FIG. FIG. 2 is a perspective view showing a part of a workpiece holding device of the screen printing machine shown in FIG. FIG. 5 is an enlarged perspective view of a portion of the work holding device shown in FIG. FIG. 1 is a partial cross-sectional view of a workpiece holding device according to an embodiment of the present disclosure. FIG. 2 is a block diagram showing a control system of the screen printing machine shown in FIG. FIG. 2 is an explanatory diagram of the operation of the screen printing machine shown in FIG. FIG. 2 is an explanatory diagram of the operation of the screen printing machine shown in FIG. FIG. 7 is an explanatory diagram of a top clamper extending operation during a clamping operation of the work holding device shown in FIG. FIG. 10 is an explanatory diagram of the extension operation of the top clamper, following FIG. FIG. 11 is an explanatory diagram of the extension operation of the top clamper subsequent to FIG. 10 . FIG. 12 is an explanatory diagram of a clamping operation of a workpiece holding device in a screen printing machine, showing the state shown in FIG. 11; FIG. 12B is an explanatory diagram of the clamping operation subsequent to FIG. 12A. FIG. 12B is a perspective view showing the workpiece holding device shown in FIG. 12A together with a substrate; FIG. 12C is a perspective view showing the workpiece holding device shown in FIG. 12B together with a substrate; FIG. 12C is a partial enlarged view of the work holding device in the state shown in FIG. FIG. 12B is an explanatory diagram of the clamping operation of the workpiece holding device; FIG. 15B is an explanatory diagram of the clamping operation of the workpiece holding device subsequent to FIG. 15A; FIG. 15B is a partial enlarged view of the work holding device in the state shown in FIG. FIG. 17 is an explanatory diagram of a storing operation of a top clamper in the clamping operation of the work holding device shown in FIG. 16 . FIG. 18 is an explanatory diagram of the storing operation of the top clamper subsequent to FIG. 17; FIG. 19 is an explanatory diagram of the storing operation of the top clamper subsequent to FIG. 18 . FIG. 4 is an explanatory diagram of the operation of the screen printing machine shown in FIG. FIG. 4 is an explanatory diagram of the operation of the screen printing machine shown in FIG.

Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Figs. 1, 2, and 3 show a screen printing machine 1 according to an embodiment of the present disclosure. The screen printing machine 1 applies a paste such as solder paste to an electrode pattern 2D formed on the upper surface of a substrate 2. The screen printing machine 1 has a base 11, a stage 12, a substrate holding mechanism 13 as a work holding device, an input conveyor 14, an output conveyor 15, a mask plate 16, a squeegee moving mechanism 17, two squeegees 18, and a camera 19. For convenience, in the following description, the left and right directions as seen from the operator OP shown in Fig. 1 are defined as the X-axis, and the front and back directions as seen from the operator OP are defined as the Y-axis. The top and bottom directions are defined as the Z-axis.

As shown in Figures 2 and 3, the stage 12 is provided on the base 11. As shown in Figure 3, the stage 12 has a Y-axis driver 12a, an X-axis driver 12b, a θ-axis driver 12c, a Z-axis driver 12d, and a moving stage 12e. The moving stage 12e is located at the top of the stage 12. The Y-axis driver 12a moves the moving stage 12e along the Y-axis, and the X-axis driver 12b drives the moving stage 12e along the X-axis. The θ-axis driver 12c rotates the moving stage 12e around the Z-axis, and the Z-axis driver 12d moves the moving stage 12e along the Z-axis.

The substrate holding mechanism 13 is provided on the moving stage 12e. As shown in FIG. 3, the substrate holding mechanism 13 has a support unit 21, a lifting motor 22, a pair of front and rear conveyor support members 23, an intermediate conveyor 24, a side clamper 25, and a clamp cylinder 26.

The support unit 21 is located above the moving stage 12e and has a plate-shaped base portion 21a at its bottom. The lifting motor 22 raises and lowers the base portion 21a relative to the moving stage 12e, thereby raising and lowering the entire support unit 21. Each of the conveyor support members 23 extends upward from the top surface of the moving stage 12e and extends upward through the base portion 21a.

Figure 4 is a perspective view showing a part of the substrate holding mechanism 13. As shown in Figures 3 and 4, the intermediate conveyors 24 are provided in a one-to-one correspondence with the conveyor support members 23. The intermediate conveyors 24 support both ends of the substrate 2 in the direction in which the Y axis extends from below, transport the substrate 2 along the X axis, and position the substrate 2. The side clampers 25 are provided in a one-to-one correspondence with the upper end of the conveyor support members 23. The side clampers 25 are arranged so that their side end faces face each other in the front-to-rear direction.

As shown in FIG. 4, the side clamper 25 is composed of a plate-shaped member extending along the X-axis. The dimension of the side clamper 25 along the X-axis is set to be larger than the maximum length of the substrate 2 along the X-axis, and the dimension of the side clamper 25 along the Z-axis is set to be larger than the maximum thickness of the substrate 2.

The clamp cylinders 26 are each attached to a bracket 23B. The bracket 23B is provided on the upper part of the conveyor support member 23. The clamp cylinders 26 have a clamp cylinder rod 26R, which is a piston rod. The clamp cylinder rod 26R is connected to the outer end face of the side clamper 25. When the clamp cylinders 26 advance the clamp cylinder rods 26R, the side clampers 25 move inward. That is, the side clampers 25 move in a direction that closes the gap between them. When the clamp cylinders 26 retract the clamp cylinder rods 26R, the side clampers 25 move outward. That is, the side clampers 25 move in a direction that opens the gap between them.

Figure 5 is an enlarged perspective view of a portion of the substrate holding mechanism 13, and Figure 6 is a partial cross-sectional view of the substrate holding mechanism 13. As shown in Figures 4, 5, and 6, each side clamper 25 is provided with a top clamper 27 used when clamping opposing end surfaces of the substrate 2, and a top clamper moving mechanism 28 that moves the top clamper 27. The top clamper 27 and the top clamper moving mechanism 28 will be described later. Thus, the pair of side clampers 25 is a first side clamper and a second side clamper, with the first side clamper provided with a first top clamper and the second side clamper provided with a second top clamper.

As shown in Figures 1 and 2, a pair of input conveyors 14 are provided upstream (to the left) of the intermediate conveyor 24, and a pair of output conveyors 15 are provided downstream (to the right) of the intermediate conveyor 24. The input conveyors 14 receive the substrate 2 fed from outside the screen printing machine 1, carry it into the screen printing machine 1, and transfer it to the intermediate conveyor 24. The output conveyor 15 carries the substrate 2 received from the intermediate conveyor 24 out of the screen printing machine 1.

As shown in Figures 1, 2 and 3, the mask plate 16 is a rectangular plate-like member, and is supported from the periphery by a frame 16W. A pattern hole 16H corresponding to the electrode pattern 2D formed on the substrate 2 is provided in the central region of the mask plate 16.

As shown in Figures 1 and 2, the squeegee movement mechanism 17 is composed of two fixed beams 17a and a moving beam 17b. The fixed beams 17a extend along the Y axis above the left and right sides of the base 11. The moving beam 17b extends along the X axis, and both ends of the moving beam 17b are supported by the two fixed beams 17a. The moving beam 17b is moved along the Y axis by a beam movement mechanism (not shown).

As shown in Figures 2 and 3, the two squeegees 18 are attached to the moving beam 17b. Therefore, as the moving beam 17b moves along the Y axis, the two squeegees 18 move along the Y axis above the mask plate 16.

As shown in Figures 1 and 2, the two squeegees 18 each have a shape that extends along the X-axis, and are arranged opposite each other along the Y-axis below the moving beam 17b. The two squeegees 18 can each be raised and lowered individually by a squeegee up-and-down movement cylinder 18K attached to the upper surface of the moving beam 17b.

As shown in FIG. 3, the camera 19 moves in a horizontal plane below the mask plate 16 by the operation of the camera movement mechanism 19K. The camera 19 can capture images of both the area below the camera 19 and the area above the camera 19.

Here, the above-mentioned top clamper 27 and top clamper movement mechanism 28 will be described. As shown in Figures 4, 5 and 6, the side clamper 25 has a storage space 25S that extends along the X-axis and is recessed downward from the upper surface. The top clamper 27 is a plate-shaped member that is thinner than the side clamper 25 and extends along the X-axis, and has a shape that can be stored in the storage space 25S. When the top clamper 27 is stored in the storage space 25S, the dimensions may be designed so that the upper surface of the top clamper 27 is approximately the same height as the upper surface of the side clamper 25. Specifically, the height of the upper surface of the top clamper 27 may be the same as the height of the upper surface of the side clamper 25, or may be higher than the upper surface of the side clamper 25 by within a range of 0.3 mm. In this state, the mask plate 16 can be supported by the upper surfaces of the top clamper 27 and the side clamper 25, and the paste can be printed stably. In particular, it is preferable that the height of the upper surface of the top clamper 27 is the same as the height of the upper surface of the side clamper 25.

Each top clamper movement mechanism 28 moves one of the top clampers 27 relative to the side clamper 25. Each top clamper movement mechanism 28 has a slider 31, two sets of parallel links 32, a lifting cylinder 33, and two slide cylinders 34.

As shown in Figures 4 and 5, two end extensions 27B extending downward are attached to the underside of both ends of the top clamper 27 in the direction in which the X-axis extends. In addition, a gate-shaped central extension 27R extending downward is attached to the center of the top clamper 27 in the direction in which the X-axis extends.

As shown in Figures 5 and 6, the inner end of the top clamper 27 protrudes further inward than the two end extensions 27B and the central extension 27R attached to the top clamper 27. The inner side of the top clamper 27 is the side where the top clampers 27 face each other. Hereinafter, the protruding end of the top clamper 27 is referred to as the protruding end 27T, as shown in Figure 6.

As shown in Figures 5 and 6, the slider 31 is composed of a plate-shaped member that extends along the X-axis below the side clamper 25. The slider 31 is attached to each of the conveyor support members 23 so as to be slidable along the Y-axis.

As shown in Figures 5 and 6, each of the two sets of parallel links 32 is composed of two rod members arranged in parallel. The lower end of each rod is rotatably supported by an upward extension 31B that extends upward from the slider 31. The upper end of each rod is rotatably supported by an end extension 27B that extends downward from the top clamper 27.

As shown in Figures 4, 5 and 6, the lift cylinder 33 is provided on a cylinder mount portion 31M formed on the upper surface of the center portion of the slider 31. The lift cylinder 33 has a lift cylinder rod 33R, which is a piston rod. The lift cylinder rod 33R faces inward. The inner side is the same side as the inner side of the top clamper 27 described above. The tip of the lift cylinder rod 33R is inserted into the central extension portion 27R extending downward from the top clamper 27. A connecting pin 33P is attached to the tip of the lift cylinder rod 33R. The connecting pin 33P extends along the X-axis and is inserted into a long hole provided on the side of the central extension portion 27R. Therefore, the tip of the lift cylinder rod 33R is slightly movable along the Z-axis relative to the central extension portion 27R. In other words, the tip of the lift cylinder rod 33R is slightly movable along the Z-axis relative to the top clamper 27.

The two slide cylinders 34 are attached to the underside of both ends of the side clamper 25. The slide cylinders 34 have a slide cylinder rod 34R, which is a piston rod. The slide cylinder rod 34R faces outward. The outward side is the opposite side to the inside of the top clamper 27 mentioned above. The slide cylinder rod 34R is connected to a connecting portion 31K. The connecting portion 31K extends upward from both ends of the slider 31.

Figure 7 is a block diagram showing the control system of the screen printing machine 1. The control device 40 of the screen printing machine 1 controls the operation of the stage 12, the substrate holding mechanism 13, the carry-in conveyor 14, the carry-out conveyor 15, the squeegee moving mechanism 17, the squeegee up-down movement cylinder 18K, and the camera 19. In controlling the operation of the stage 12, the control device 40 controls each of the Y-axis drive unit 12a, the X-axis drive unit 12b, the θ-axis drive unit 12c, and the Z-axis drive unit 12d. In controlling the operation of the substrate holding mechanism 13, the control device 40 controls each of the lift motor 22, the intermediate conveyor 24, the clamp cylinder 26, and the top clamper moving mechanism 28 (lift cylinder 33 and slide cylinder 34).

Next, the operation of the screen printing machine 1 will be described with reference to Figures 8A to 20B. When the control device 40 of the screen printing machine 1 receives the substrate 2 from another device located upstream as shown by arrow A in Figure 8A, it operates the carry-in conveyor 14 to receive the substrate 2 and carry it into the screen printing machine 1. Then, as shown in Figure 8B, the carry-in conveyor 14 passes the substrate 2 to the intermediate conveyor 24 of the substrate holding mechanism 13. The intermediate conveyor 24 transports the received substrate 2 to a predetermined position. Once the intermediate conveyor 24 has transported the substrate 2 to the predetermined position, the substrate holding mechanism 13 clamps and holds the substrate 2.

For the substrate holding mechanism 13 to hold the substrate 2, the lift cylinder 33 first retracts the lift cylinder rod 33R as shown by the arrow F1 in FIG. 9. This causes the connecting pin 33P of the lift cylinder rod 33R to move outward (to the right in FIG. 9) along the central extension 27R. As a result, the top clamper 27 moves outward via the parallel link 32. At this time, the top clamper 27 moves slightly upward relative to the connecting pin 33P at the tip of the lift cylinder rod 33R. As a result, the top clamper 27 as a whole moves outward and upward relative to the side clamper 25 as shown by the arrow R1.

When the top clamper 27 moves to the outside and above the side clamper 25, the slide cylinder 34 retracts the slide cylinder rod 34R, as shown by arrow F2 in Figure 10. This causes the slider 31 to slide inward (to the left in Figure 10) relative to the conveyor support member 23. As a result, the top clamper 27 moves inward above the side clamper 25, as shown by arrow M1. In other words, the top clampers 27 move in directions that bring them closer to each other.

When the top clamper 27 moves inward, the lift cylinder 33 advances the lift cylinder rod 33R, as shown by arrow F3 in FIG. 11. This causes the lift cylinder rod 33R to move the central extension 27R inward (to the left in FIG. 11) via the connecting pin 33P. As a result, the top clamper 27 moves inward via the parallel link 32. At this time, the top clamper 27 moves slightly downward relative to the connecting pin 33P. As a result, the top clamper 27 as a whole moves inward and downward relative to the side clamper 25, as shown by arrow R2.

As a result, the protruding end 27T protrudes inward from the inner end surface of the side clamper 25. When the above operation is performed on both side clampers 25 and the top clamper 27, as shown in FIG. 12A, the protruding end 27T of each of the top clampers 27 protrudes into the area between the side clampers 25. In this way, the position where each of the protruding end 27T of the top clamper 27 protrudes into the area between the side clampers 25 is called the "extended position" of the pair of top clampers 27. More specifically, the first top clamper protrudes to the first extended position, and the second top clamper protrudes to the second extended position. In this embodiment, the top clamper 27 and the side clamper 25 provided on each of the conveyor support members 23 may be configured so that the lower surface of the top clamper 27 in the extended position is at the same height as the upper surface of the side clamper 25. That is, the lower surface of the first top clamper in the first protruding position may be at the same height as the upper surface of the first side clamper, and the lower surface of the second top clamper in the second protruding position may be at the same height as the upper surface of the second side clamper. In other words, the lower surface of the top clamper 27 may be in contact with the upper surface of the side clamper 25. If the substrate 2 is warped, the warp may be corrected by the force of the side clamper 25 clamping the substrate 2. When performing such an operation, if the lower surface of the top clamper 27 is at the same height as the upper surface of the side clamper 25, the substrate 2 can be prevented from abutting against the lower surface of the top clamper 27 and deforming the substrate 2 more than necessary. As a result, the substrate 2 and the side clamper 25 can be in close contact with the mask plate 16 during printing, and the printing quality of the paste on the substrate 2 can be ensured.

When each protruding end 27T of the top clamper 27 protrudes into the area between the side clampers 25, the lifting motor 22 raises the support unit 21 as shown by the arrow L in FIG. 12B. This causes the support unit 21 to push up the substrate 2 on the intermediate conveyor 24. In other words, the substrate holding mechanism 13 transitions from the state shown in FIG. 12A and FIG. 13A to the state shown in FIG. 12B and FIG. 13B. In this way, the support unit 21 functions as a push-up section that pushes up the substrate 2, which is the workpiece.

When the lower support unit 21 pushes up the substrate 2, as shown in Figures 12B, 13B, and 14, the upper surfaces of both ends of the substrate 2 in the direction in which the Y axis extends come into contact with the lower surface of each of the protruding ends 27T of the top clamper 27 from below. Therefore, the height of the upper surface of the substrate 2 is the height of the lower surface of the top clamper 27, i.e., the height of the upper surface of the side clamper 25.

When both ends of the substrate 2 come into contact with the protruding ends 27T from below, the lifting motor 22 stops lifting the support unit 21. That is, the control device 40 stops the support unit 21 from pushing up the substrate 2. Then, when the support unit 21 stops pushing up the substrate 2, the clamp cylinders 26 advance their respective clamp cylinder rods 26R as shown by the arrow P in FIG. 15A and FIG. 16. When the clamp cylinders 26 advance their respective clamp cylinder rods 26R, the side clampers 25 move inward as shown by the arrow M2 in FIG. 16. That is, the side clampers 25 move closer to each other. As a result, the inner end faces of the side clampers 25 come into contact with one of the end faces of the substrate 2 in the direction in which the Y axis extends. As a result, both end faces of the substrate 2 are clamped by the side clampers 25 as shown in FIG. 15A.

In this embodiment, the pair of clamp cylinders 26, together with the control device 40, constitute a side clamper drive unit that drives the side clampers 25 in a direction to close each other, thereby clamping both opposing end surfaces of the substrate 2 as a workpiece with the side clampers 25.

When the side clampers 25 clamp both end surfaces of the substrate 2, the lift cylinder 33 retracts the lift cylinder rod 33R, as shown by arrow F4 in FIG. 17. This causes the connecting pin 33P of the lift cylinder rod 33R to move the central extension 27R outward (to the right in FIG. 17). As a result, the top clamper 27 moves outward and upward via the parallel link 32, as shown by arrow R3.

When the top clamper 27 moves outward and upward, the slide cylinder 34 advances the slide cylinder rod 34R, as shown by arrow F5 in FIG. 18. When the slide cylinder 34 advances the slide cylinder rod 34R, the slider 31 slides outward (to the right in FIG. 18) relative to the conveyor support member 23. As a result, the top clamper 27 moves outward above the side clamper 25, as shown by arrow M3. In other words, the top clampers 27 move in directions away from each other. As a result, the protruding ends 27T of the top clampers 27 retract into the upper region of the side clampers 25.

When the top clamper 27 retracts into the upper region of the side clamper 25, the lift cylinder 33 advances the lift cylinder rod 33R, as shown by the arrow F6 in FIG. 19. When the lift cylinder rod 33R advances, the connecting pin 33P of the lift cylinder rod 33R moves the central extension 27R inward (to the left in FIG. 19). As a result, the top clamper 27 moves inward and downward via the parallel link 32, as shown by the arrow R4. In other words, the top clamper 27 descends. As a result, the top clamper 27 moves to a position stored in the storage space 25S that opens on the upper surface of the side clamper 25, as shown in FIG. 19. The position where the top clamper 27 is stored is called the storage position. In this way, the substrate 2 is held by the substrate holding mechanism 13, as shown in FIG. 15B.

In this manner, in this embodiment, the top clamper moving mechanism 28 performs a storage operation and an extension operation. In the storage operation, each of the top clampers 27 is stored in the storage space 25S from the extension position. In the extension operation, the top clamper 27 stored in the storage space 25S moves to the extension position. The storage space 25S in which each of the top clampers 27 is stored is recessed downward from the upper surface of each of the side clampers. Therefore, the movement path of the top clamper 27 when moving the top clamper 27 from the storage position to the extension position and from the extension position to the storage position is extremely short. In this manner, the pair of top clamper moving mechanisms 28 and the control device 40 constitute a top clamper moving section. This top clamper moving section moves the first top clamper of the top clampers 27 between the first storage position and the first extension position, and moves the second top clamper of the top clampers 27 between the second storage position and the second extension position.

In addition, in this embodiment, the storage and extension operations by the top clamper movement mechanism 28 are each composed of a combination of a lifting operation and a horizontal movement operation. In the lifting operation, the lifting cylinder 33 lifts and lowers each of the top clampers 27. In the horizontal movement operation, the slide cylinder 34 moves the top clampers 27 in a direction to move them closer to each other or away from each other. Therefore, the movement path when moving the top clampers 27 from the storage position to the extension position and from the extension position to the storage position is extremely short.

When the substrate holding mechanism 13 has completed holding the substrate 2, the control device 40 activates the camera movement mechanism 19K to position the camera 19 between the substrate 2 held by the substrate holding mechanism 13 and the mask plate 16. The control device 40 then causes the camera 19 to capture images of the substrate mark (not shown) provided on the substrate 2 and the mask mark (not shown) provided on the mask plate 16. When the camera 19 captures images of the substrate mark and the mask mark, the control device 40 determines the position of the substrate 2 relative to the mask plate 16 based on the image data of these marks.

After determining the position of the substrate 2 relative to the mask plate 16, the control device 40 controls the stage 12 to move the substrate 2 in a horizontal plane. The control device 40 then aligns the substrate 2 in the horizontal plane so that the substrate mark and the mask mark face each other vertically. This aligns the substrate 2 with respect to the mask plate 16. After aligning the substrate 2, the control device 40 operates the stage 12 to raise the entire substrate holding mechanism 13, as shown by the arrow H in FIG. 20A. This causes the control device 40 to bring the upper surface of the substrate 2 into contact with the lower surface of the mask plate 16 from below, as shown in FIG. 20B. This causes the pattern holes 16H of the mask plate 16 to match the electrode pattern 2D on the substrate 2.

When the substrate 2 comes into contact with the mask plate 16, the control device 40 lowers one of the squeegees 18 so that the lower edge of the lowered squeegee 18 abuts against the upper surface of the mask plate 16. Then, as shown by the arrow G in FIG. 20B, the squeegee 18 abutting against the mask plate 16 is moved along the Y axis, and the paste Pst is scraped up by the squeegee 18. This action fills the pattern holes 16H of the mask plate 16 with the paste Pst.

When the paste Pst is filled into the pattern holes 16H of the mask plate 16, the paste Pst is printed onto the electrode pattern 2D of the substrate 2. After this, the control device 40 operates the stage 12 to lower the entire substrate holding mechanism 13, separating the substrate 2 from the mask plate 16, and the plate is detached.

When plate separation is complete, the control device 40 activates the clamp cylinder 26 and moves the side clampers 25 away from each other to release the clamp on the substrate 2. The control device 40 then lowers the support unit 21 relative to the moving stage 12e to lower the substrate 2 onto the intermediate conveyor 24. The control device 40 then activates the intermediate conveyor 24 and the discharge conveyor 15 to transfer the substrate 2 on the intermediate conveyor 24 to the discharge conveyor 15. After the discharge conveyor 15 receives the substrate 2 from the intermediate conveyor 24, it discharges the substrate 2 outside the screen printing machine 1.

As described above, in the screen printing machine 1 having the substrate holding mechanism 13, the storage space 25S for the top clamper 27 is recessed from the upper surface of the side clamper 25 (opens to the upper surface). Therefore, the movement path when moving the top clamper 27 from the storage position to the extended position and from the extended position to the storage position is extremely short. Therefore, the top clamper 27 can be moved in a compact configuration, and the screen printing machine 1 can be prevented from becoming large.

Although the embodiment of the present disclosure has been described above, the present disclosure is not limited to the above, and various modifications and the like are possible. For example, in the above embodiment, after the pair of side clampers 25 clamp both end surfaces of the substrate 2, the top clamper 27 is stored in the storage space 25S. However, when the thickness (dimension along the Z axis) of the top clamper 27 is extremely small, the substrate 2 may be brought into contact with the mask plate 16 and screen printing may be performed without storing the top clamper 27 in the storage space 25S. The storage space 25S is also provided with an opening on the upper surface of the side clamper 25. More specifically, in the example shown in FIG. 13B, the storage space 25S is rectangular in size to accommodate the top clamper 27 and penetrates the side clamper 25. However, as long as the top clamper 27 can be stored, it does not have to penetrate except for the portions through which the end extensions 27B and the central extensions 27R are inserted. In particular, when the thickness of the top clamper 27 is extremely small, the upper surface of the side clamper 25 may be used as the storage space 25S. In other words, the storage space 25S does not necessarily have to be recessed from the top surface of the side clamper 25. In this way, the storage space 25S only needs to be provided on the top surface side of the side clamper 25.

The above-described configuration of the top clamper moving mechanism 28 is merely one example. As long as the top clamper 27 can be stored in the storage space 25S provided on the upper surface side of the side clamper 25 and the top clamper 27 can be moved from the storage space 25S to the extended position, other configurations are also acceptable.

In the workpiece holding device and screen printing machine disclosed herein, the top clamper can be moved in a compact configuration, and the overall size of the device can be prevented from increasing. Therefore, the workpiece holding device and screen printing machine are industrially useful from the standpoint of space saving.

1 Screen printing machine 2 Substrate (work)
2D electrode pattern 11 Base 12 Stage 12a Y-axis drive unit 12b X-axis drive unit 12c θ-axis drive unit 12d Z-axis drive unit 12e Moving stage 13 Substrate holding mechanism (work holding device)
14: carry-in conveyor 15: carry-out conveyor 16: mask plate 16H: pattern hole 16W: frame 17: squeegee movement mechanism 17a: fixed beam 17b: movement beam 18: squeegee 18K: squeegee up-down movement cylinder 19: camera 19K: camera movement mechanism 21: lower support unit (workpiece push-up section)
21a Base portion 22 Lifting motor 23 Conveyor support member 23B Bracket 24 Intermediate conveyor 25 Side clamper 25S Storage space 26 Clamp cylinder 26R Clamp cylinder rod 27 Top clamper 27B End extension portion 27R Central extension portion 27T Protruding end portion 28 Top clamper moving mechanism 31 Slider 31B Upward extension portion 31K Connecting portion 31M Cylinder mount portion 32 Parallel link 33 Lifting cylinder 33P Connecting pin 33R Lifting cylinder rod 34 Slide cylinder 34R Slide cylinder rod 40 Control device Pst Paste

Claims (5)

A lifting section that lifts up the workpiece;
a first side clamper and a second side clamper that clamp the workpiece pushed up by the push-up unit at both opposing end surfaces of the workpiece;
a side clamper drive unit that causes the first and second side clampers to clamp both end surfaces of the workpiece;
a first top clamper movable between a first storage position and a first extended position above the first side clamper; and a second top clamper movable between a second storage position and a second extended position above the second side clamper.
a top clamper moving unit that moves the first top clamper between the first stored position and the first extended position and moves the second top clamper between the second stored position and the second extended position,
a first storage space for storing the first top clamper positioned at the first storage position is provided on an upper surface side of the first side clamper, and a second storage space for storing the second top clamper positioned at the second storage position is provided on an upper surface side of the second side clamper,
The first top clamper is in contact with an upper surface of the workpiece at one of both ends of the workpiece pushed up by the push-up unit from below at the first protruding position, and the second top clamper is in contact with an upper surface of the workpiece at the other of both ends of the workpiece pushed up by the push-up unit from below at the second protruding position,
a top clamper moving section that moves the first and second top clampers via a parallel link mechanism, and a slide cylinder that moves the first and second top clampers toward each other or away from each other. When the top clamper moving unit moves the first top clamper to the first extended position and moves the second top clamper to the second extended position, the first and second top clampers are raised by the lifting cylinder, the first and second top clampers are moved closer to each other by the slide cylinder, and the first and second top clampers are lowered by the lifting cylinder,
When the top clamper moving unit moves the first top clamper to the first storage position and moves the second top clamper to the second storage position, the first and second top clampers are raised by the lift cylinder, and then the first and second top clampers are moved in directions away from each other by the slide cylinder, and the first and second top clampers are lowered by the lift cylinder.
The workpiece holding device according to claim 1 . a lower surface of the first top clamper in a state where the first top clamper is positioned at the first extended position is substantially at the same height as an upper surface of the first side clamper, and a lower surface of the second top clamper in a state where the second top clamper is positioned at the second extended position is substantially at the same height as an upper surface of the second side clamper.
The workpiece holding device according to claim 1 or 2. an upper surface of the first top clamper stored in the first storage space is flush with an upper surface of the first side clamper, and an upper surface of the second top clamper stored in the second storage space is flush with an upper surface of the second side clamper;
The workpiece holding device according to claim 1 or 2. A workpiece holding device according to any one of claims 1 to 4,
a mask plate having pattern holes and contacting an upper surface of the work clamped by the first and second side clampers of the work holding device;
a squeegee that slides over the mask plate in contact with the top surface of the workpiece to scrape up the paste on the mask plate, thereby applying the paste to the top surface of the workpiece through the pattern holes.

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