WO2018193773A1 - Screen printing device and screen printing method - Google Patents

Abstract

Screen printing a plurality of workpieces to be printed on, which are arranged on a carrier, comprises: holding the plurality of workpieces under a mask plate having printing pattern holes formed therein; arraying the plurality of workpieces on the carrier in accordance with an arrangement of the pattern holes; moving a carrier holding part and the mask plate relative to each other to align the plurality of arrayed workpieces and the mask plate with each other; and printing a paste from an upper surface of the mask plate onto the plurality of arrayed workpieces via the pattern holes.

Description

Screen printing apparatus and screen printing method

The present disclosure relates to a screen printing apparatus and a screen printing method for printing a paste on a workpiece such as a substrate.

In the field of electronic component manufacturing, screen printing is widely used as a method for printing paste such as cream solder or conductive paste on a substrate. In the case where the substrate to be printed is a small-sized individual substrate divided into individual pieces, the printing operation is performed in a state where a plurality of individual substrates are arranged on a handling carrier. As a carrier used in such screen printing, a carrier having a work placement portion for holding an individual substrate on a rectangular plate-like member is known (see, for example, Patent Document 1).

In the prior art shown in this patent document example, a print target substrate to be printed out of a plurality of individual substrates placed on a carrier (pallet) is first lifted from the carrier by a backup device. Next, position detection is performed to correctly align the individual substrate with the opening of the screen mask. Based on the position detection result, the individual substrate is brought into contact with the opening of the screen mask, and screen printing is performed on the substrate to be printed. Like to do. These series of operations are sequentially executed for each of the plurality of individual substrates. By using such a method, there is an advantage that high positional accuracy can be ensured by correcting the positional deviation of the individual substrate in a state where it is placed on the carrier.

International Publication No. 2017/022127

However, according to the prior art shown in the above-mentioned patent document, a series of work steps for performing screen printing on a print target substrate are sequentially executed for each of the plurality of individual substrates, and thus the entire plurality of individual substrates is There is a problem that it is difficult to improve productivity due to a delay in the work time. That is, in the screen printing operation, the work time in the squeegeeing operation in which the squeegee is moved on the upper surface of the screen mask in a state where the substrate is in contact with the lower surface accounts for a large proportion of the entire work time. For this reason, in the screen printing method in which squeezing is repeatedly performed for each of a plurality of individual substrates as in the prior art described above, there is a limit to shortening the work time, and it has been difficult to significantly improve productivity. As described above, the conventional technique has a problem that it is difficult to ensure high productivity in a method of correcting the positional deviation of a workpiece such as an individual substrate placed on a carrier to ensure printing accuracy.

Therefore, the present disclosure aims to provide a screen printing apparatus and a screen printing method that can secure high productivity while correcting the positional deviation of a workpiece placed on a carrier to ensure printing accuracy. .

The screen printing apparatus of the present disclosure includes a mask plate in which a pattern hole for printing is formed, a carrier holding unit that holds a carrier in which a plurality of workpieces are arranged below the mask plate, and a plurality of workpieces on the carrier. An alignment unit configured to align with the arrangement of the pattern holes, an alignment mechanism configured to relatively move the carrier holding unit and the mask plate to align the plurality of aligned workpieces and the mask plate, and the mask plate And a print head for printing a paste on the plurality of workpieces aligned from the upper surface of the substrate through the pattern holes.

The screen printing method of the present disclosure includes a carrier holding step for holding a carrier in which a plurality of workpieces are arranged below a mask plate in which pattern holes for printing are formed, and a plurality of workpieces on the carrier are arranged in the pattern holes. An alignment step of aligning the plurality of aligned workpieces with the mask plate, an alignment step of relatively moving the carrier holding portion and the mask plate to align the mask plate, and alignment from the upper surface of the mask plate And a printing step of printing paste on the plurality of workpieces through the pattern holes.

According to the present disclosure, it is possible to ensure high productivity while securing the printing accuracy by correcting the positional deviation of the workpiece placed on the carrier.

FIG. 1 is a front view of a screen printing apparatus according to an embodiment of the present disclosure. FIG. 2 is a side view of the screen printing apparatus according to the embodiment of the present disclosure. FIG. 3 is a perspective view of a carrier that holds a workpiece to be printed by the screen printing apparatus according to the embodiment of the present disclosure. FIG. 4 is an explanatory diagram of the work holding by the carrier in the screen printing apparatus according to the embodiment of the present disclosure. FIG. 5 is an explanatory diagram of workpiece suction and holding in the screen printing apparatus according to the embodiment of the present disclosure. FIG. 6 is a block diagram illustrating a configuration of a control system of the screen printing apparatus according to the embodiment of the present disclosure. FIG. 7 is a flowchart illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 8 is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 9 is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 10 is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 11 is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 12 is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 13 is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 14 is an explanatory diagram of the alignment between the workpiece and the mask plate in the screen printing method according to the embodiment of the present disclosure. FIG. 15A is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 15B is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 15C is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 16 is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 17 is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 18A is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 18B is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 19 is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure. FIG. 20 is an operation explanatory diagram illustrating a screen printing method according to an embodiment of the present disclosure.

Next, an embodiment of the present disclosure will be described with reference to the drawings. First, the overall configuration of the screen printing apparatus 1 will be described with reference to FIGS. 1 and 2. The screen printing apparatus 1 has a function of printing paste such as cream solder on a workpiece such as a substrate. 1 and 2, support frames 11 are erected on both sides of the base 1a in the X direction, and the following elements constituting the screen printing apparatus 1 are provided between the pair of support frames 11. Is arranged. In the present embodiment, the horizontal direction in FIG. 1, that is, the workpiece conveyance direction for conveying the work target carrier 9 is defined as the X direction, and the direction orthogonal to the X direction is defined as the Y direction. As shown in FIG. 3, the carrier 9 is a rectangular workpiece holder, and holds a plurality of workpieces 10 such as substrates in a predetermined regular arrangement.

A printing stage 2 that is moved by a printing stage moving mechanism 3 is disposed on the upper surface of the base 1 a between the pair of support frames 11. The printing stage moving mechanism 3 has a structure in which a printing stage elevating mechanism 3z is stacked on a printing stage XYΘ table 3xyθ. By driving the printing stage XYΘ table 3xyθ, the printing stage 2 moves in the X direction, Y direction, and Θ direction. The printing stage 2 moves up and down by moving horizontally and driving the printing stage lifting mechanism 3z.

The printing stage 2 has a function of holding a carrier 9 (see FIG. 3) on which a work 10 to be printed that is carried in from the upstream side is arranged and aligning it with a screen printing mechanism described below. Yes. The screen printing mechanism includes a mask plate 22 in which a pattern hole 22a for printing (see FIG. 14) is formed, and a print head 13 that performs a squeezing operation on the mask plate 22.

The printing stage 2 includes a lifting table 4 coupled to the upper surface of the printing stage lifting mechanism 3z. Support members 4a are erected on both ends of the upper surface of the lift table 4, and as shown in FIG. 2, a holding block 4b extending in the X direction is coupled to the upper end of the support member 4a. A printing stage conveyor 6b having a driving belt for conveying the workpiece 10 is provided on the inner surface of the holding block 4b.

The printing stage conveyor 6b can be connected to a carry-in conveyor 6a and a carry-out conveyor 6c arranged through openings provided in the upstream and downstream support frames 11, respectively. The workpiece 10 carried in (arrow a) by the carry-in conveyor 6a is transferred to the printing stage conveyor 6b and held by the printing stage 2. The workpiece 10 after the screen printing is completed in the printing stage 2 is transferred from the printing stage conveyor 6b to the carry-out conveyor 6c and is carried out.

On the upper surface of the elevating table 4, a backup unit 5 that is driven up and down by a backup elevating mechanism 5a is disposed. In a state where the carrier 9 is carried into the printing stage conveyor 6b, the backup lifting mechanism 5a is driven to raise the backup unit 5, thereby lifting the carrier 9 conveyed by the printing stage conveyor 6b from the lower surface side, and the workpiece 10 Can be held at the printing height position by the above-described screen printing mechanism.

Side clamps 7 are provided on the upper surfaces of the pair of holding blocks 4b. These side clamps 7 can be opened and closed with each other by a side clamp drive mechanism 7a (see FIG. 6), and by causing the side clamp 7 to perform a closing operation while receiving the carrier 9 by the backup unit 5, In the printing stage 2, the carrier 9 is clamped and fixed on both sides by the side clamps 7. In the above-described configuration, the back-up unit 5 that is placed on and received from the lower surface of the carrier 9 and the side clamp 7 that clamps the carrier 9 in this state sandwich the carrier 9 in which a plurality of workpieces 10 are arranged below the mask plate 22. It is a carrier holding part which holds.

A plurality of workpieces 10 are arranged on the carrier 9 held by the carrier holding unit, and the positions of the plurality of workpieces 10 are not necessarily in a normal state without positional deviation. For this reason, in a work mode in which printing is performed collectively with the same mask plate 22 for the carrier 9 on which a plurality of workpieces 10 are arranged, the plurality of workpieces 10 arranged on the same carrier 9 are patterned on the mask plate 22. An alignment process that matches the arrangement of the holes 22a is required. The screen printing apparatus 1 according to the present embodiment has a function as an alignment unit that aligns a plurality of workpieces 10 on the carrier 9 held by the carrier holding unit in accordance with the arrangement of the pattern holes 22a of the mask plate 22. It has become. The specific configuration of the alignment unit will be described later.

In order to align the plurality of workpieces 10 aligned in this way and the mask plate 22, the carrier holding portion that holds the carrier 9 on which the workpieces 10 are arranged is moved relative to the mask plate 22. An alignment operation is performed for alignment. That is, the printing stage XYΘ table 3xyθ that moves the printing stage 2 provided with the carrier holding portion in the horizontal direction moves the carrier holding portion and the mask plate 22 relative to each other to align the plurality of aligned workpieces 10 and the mask plate 22. Functions as an alignment mechanism.

A print head support beam 12 that supports the print head 13 is disposed at the upper ends of the pair of support frames 11 so as to be movable in the Y direction via a linear motion guide mechanism 12a. One end of the print head support beam 12 is coupled to one support frame 11 via a print head moving mechanism 14 having the configuration shown in FIG. The print head moving mechanism 14 has a configuration in which a nut portion 14c into which a feed screw 14b that is rotationally driven by a print head motor 14a is screwed is coupled to the print head support beam 12. By driving the print head motor 14a forward and backward, the print head 13 supported by the print head support beam 12 reciprocates in the Y direction which is the squeezing direction.

2, the print head 13 includes a pair of a rear squeegee 13b and a front squeegee 13c that are provided to extend downward from the print head support beam 12. By driving a squeegee driving unit 13 a provided on the upper surface of the print head support beam 12, either the rear squeegee 13 b or the front squeegee 13 c is lowered according to the squeezing direction and slidably contacts the mask plate 22.

The mask plate 22 has a pattern hole 22a for printing corresponding to the printing pattern (see FIG. 14) on the workpiece 10 to be printed. In screen printing in the screen printing apparatus 1, first, printing paste P (see FIGS. 18A and 18B) is supplied to the upper surface of the mask plate 22. The carrier 9 holding a plurality of workpieces 10 is held by the carrier holding portion described above, and the rear squeegee 13b and the front are moved on the upper surface of the mask plate 22 while the workpiece 10 to be printed is in contact with the lower surface of the mask plate 22. A squeegeeing operation of sliding any one of the squeegees 13c is performed. As a result, the paste P is printed on the workpiece 10 to be printed in a predetermined print pattern through the pattern holes 22a. That is, the print head 13 prints the paste P on the plurality of workpieces 10 aligned by the alignment unit from the upper surface of the mask plate 22 through the pattern holes 22a.

Between the upper surface of the printing stage 2 and the lower surface of the mask plate 22, the camera mounting base 17 to which the first camera 18, the second camera 19, and the work pickup unit 20 are mounted is moved in the X direction and the Y direction. A moving mechanism (see the camera moving mechanism 16 shown in FIG. 6) is provided. This moving mechanism includes a camera X axis moving mechanism 16X that moves the camera mounting base 17 in the X direction along the camera X axis beam 15, and a camera Y axis moving mechanism 16Y that moves the camera X axis beam 15 in the Y direction. The The movement of the camera X-axis beam 15 in the Y direction is guided by a linear motion guide mechanism 15 c disposed on the inner surface of the support frame 11.

The camera X-axis moving mechanism 16X includes a camera X-axis motor 15a shown in FIG. 1, a feed screw 15b, and a nut portion 15d shown in FIG. By driving the camera X-axis motor 15a, the camera mounting base 17 coupled to the nut portion 15d moves in the X direction. In FIG. 2, the camera X-axis motor 15a is not shown. As shown in FIG. 2, the camera Y-axis moving mechanism 16Y includes a camera Y-axis motor 16a, a feed screw 16b, and a nut portion 16c coupled to the camera X-axis beam 15. By driving the camera Y-axis motor 16a, the camera X-axis beam 15 coupled to the nut portion 16c moves in the Y direction.

Here, functions of the first camera 18, the second camera 19, and the work pickup unit 20 will be described. The first camera 18 is arranged with the imaging direction facing downward, and images the workpiece recognition mark 10 m (see FIG. 4) of the workpiece 10 held by the carrier 9 in the printing stage 2. The imaging result is recognized by the processing function of the workpiece recognition unit 33 (see FIG. 6), so that the position of the electrode 10a in the workpiece 10 is detected in addition to the position and direction of the workpiece 10. Therefore, the first camera 18 and the workpiece recognition unit 33 are workpiece position detection units that detect the position of the workpiece 10 that is a plurality of workpieces on the carrier 9 by imaging with the first camera 18.

The second camera 19 is arranged with the imaging direction facing upward, and images the mask recognition mark 22m formed on the mask plate 22. The imaging result is recognized by the processing function of the mask recognition unit 32 (see FIG. 6), whereby the positions of the mask center MC and the pattern hole 22a on the mask plate 22 are recognized. Therefore, the second camera 19 and the mask recognizing unit 32 are mask position detecting units that detect the position by imaging the mask plate 22 with the second camera 19.

The workpiece pick-up unit 20 is a suction holding tool having a function of holding the workpiece 10 by vacuum suction. In the present embodiment, the workpiece pickup unit 20 is used to lift at least one of the plurality of workpieces 10 on the carrier 9 from the carrier 9. It is done. As a result, it is possible to perform a workpiece alignment operation in which the workpiece 10 arranged in a misaligned state in the carrier 9 is temporarily picked up and the workpiece 10 is returned to the carrier 9 in a state in which the misalignment is corrected.

This workpiece alignment operation corrects the detected position deviation state with respect to the workpiece 10 picked up by the workpiece pickup unit 20 based on the position (position deviation state) of the workpiece 10 detected by the aforementioned workpiece position detection unit. The printing stage 2 provided with the carrier holding unit (the backup unit 5 and the side clamp 7) is moved by the printing stage XYΘ table 3xyθ relative to the horizontal direction by the correction amount necessary for this.

That is, the printing stage XYΘ table 3xyθ that relatively moves the printing stage 2 in the horizontal direction is based on the position of the workpiece 10 detected by the workpiece position detection unit described above and holds the carrier 10 and the carrier picked up by the workpiece pickup unit 20. It functions as a workpiece alignment mechanism that relatively moves the part, and this workpiece alignment mechanism also serves as the alignment mechanism described above. In the present embodiment, the alignment unit that aligns the plurality of workpieces 10 on the carrier 9 held by the carrier holding unit in accordance with the arrangement of the pattern holes 22a of the mask plate 22 is the above-described workpiece position detection unit, workpiece The pickup unit 20 and the above-described workpiece alignment mechanism are included.

In performing this alignment operation, the first camera 18 and the work pickup unit 20 are moved in a space between the mask plate 22 and the carrier holding unit (the backup unit 5 and the side clamp 7) provided in the printing stage 2. Is required. The camera movement mechanism 16 (see FIG. 6) including the camera X-axis movement mechanism 16X and the camera Y-axis movement mechanism 16Y described above includes a space between the first camera 18 and the work pickup unit 20 between the mask plate 22 and the carrier holding unit. It is a moving mechanism to move with. In the present embodiment, the camera mounting base 17 is provided as a moving member that is moved by the camera X-axis moving mechanism 16X and the camera Y-axis moving mechanism 16Y in the space between the mask plate 22 and the carrier holding portion. The first camera 18 and the work pickup unit 20 are mounted on this moving member.

Next, with reference to FIGS. 4 and 5, the holding of the carrier 9 and the work 10 by the vacuum suction in the backup unit 5 will be described. FIG. 4 shows a configuration of a workpiece storage recess 9 a formed to hold the workpiece 10 on the workpiece 10 and the carrier 9 to be printed. The workpiece 10 has a rectangular flat plate shape, and a plurality of connection electrodes 10a are formed on the upper surface. In screen printing by the screen printing apparatus 1, the electrodes are connected via the pattern holes 22a (FIG. 14) of the mask plate 22. The paste P is printed on 10a. A pair of position recognition work recognition marks 10m are formed at diagonal positions on the upper surface of the work 10.

A plurality of workpiece storage recesses 9a for receiving and holding the workpiece 10 are formed on the upper surface of the carrier 9 in a predetermined arrangement. The planar shape of the workpiece storage recess 9a is set to be somewhat larger than the outer shape of the workpiece 10 in order to facilitate the storage and removal of the workpiece 10, and has a so-called “play” state. A plurality of through holes 9b for vacuum suction are provided on the bottom surface of the workpiece housing recess 9a.

As shown in FIG. 5, the backup portion 5 is provided with a suction path 5 b opened on the upper surface at a position corresponding to the arrangement of the through holes 9 b in the carrier 9. In a state where the carrier 9 on which the workpiece 10 is disposed is held by the upper surface of the backup unit 5, the suction path 5b communicates with the through hole 9b of each workpiece storage recess 9a. The suction path 5 b of each workpiece storage recess 9 a is connected to a negative pressure generation source 24 via a control valve 23.

The control valve 23 has a function of an on / off valve that connects and disconnects the suction circuit 25 between the negative pressure generation source 24 and the suction path 5b and a function as a vacuum breaker valve that introduces the atmosphere into the suction circuit 25 in the negative pressure state. ing. By individually controlling the control valve 23 by the control unit 30 (FIG. 6), it is possible to select introduction or blocking of the negative pressure to the through hole 9b for each of the plurality of workpiece storage recesses 9a provided in the carrier 9. It has become.

In a state where the carrier 9 on which the workpiece 10 is disposed is received and held by the upper surface of the backup unit 5, the negative pressure generation source 24 is operated and the control valve 23 is opened, so that the suction path is connected via the suction circuit 25. Vacuum suction from 5b. Thereby, the workpiece | work 10 arrange | positioned in each workpiece | work storage recessed part 9a is restrained and hold | maintained by the vacuum suction to the backup part 5 with the carrier 9. FIG. When releasing the vacuum suction of the workpiece 10 and the carrier 9 to the backup unit 5, the control valve 23 is controlled so that the suction circuit 25 is closed with respect to the negative pressure generation source 24 and is opened to the atmosphere.

That is, in the above configuration, the suction path 5b formed in the backup unit 5 constituting the carrier holding unit, the suction circuit 25 connecting the suction path 5b and the negative pressure generation source 24, and the control valve 23 interposed in the suction circuit 25. The negative pressure generation source 24 constitutes a workpiece suction portion that introduces a negative pressure into the through hole 9 b that penetrates the carrier 9 in the thickness direction and restrains the plurality of workpieces 10 on the carrier 9 to the carrier 9. The workpiece suction portion can select introduction and blocking of negative pressure for each workpiece 10 disposed in each of the plurality of through holes 9 b formed in the carrier 9.

With such a configuration, of the plurality of workpieces 10 arranged and loaded in each of the workpiece storage recesses 9a of the same carrier 9, any one workpiece 10 is lifted from the workpiece storage recess 9a by the workpiece pickup unit 20, In addition, the carrier 9 can be returned to the work storage recess 9a and restrained.

Next, the configuration of the control system of the screen printing apparatus 1 will be described with reference to FIG. In FIG. 6, the control unit 30 includes a print head 13, a print head moving mechanism 14, a first camera 18, a second camera 19, a work pickup unit 20, a camera moving mechanism 16, a control valve 23, and a backup lifting mechanism 5a. The printing stage elevating mechanism 3z, the printing stage XYΘ table 3xyθ, the side clamp drive mechanism 7a, the printing stage conveyor 6b, the carry-in conveyor 6a, and the carry-out conveyor 6c are connected.

Further, the control unit 30 includes an alignment processing unit 31, a mask recognition unit 32, a work recognition unit 33, and a print processing unit 34 as internal processing functions. Further, the control unit 30 includes a storage unit 35 for storing information necessary for the control processing by them, and the storage unit 35 stores a mask pattern for storing positional information of the mask reference mark 22m and the pattern hole 22a on the mask plate 22. A position storage unit 35a is provided.

The alignment processing unit 31 performs processing for correctly aligning the plurality of workpieces 10 arranged on the carrier 9 held by the carrier holding unit provided in the printing stage 2 according to the arrangement of the pattern holes 22a of the mask plate 22. Do. The mask recognizing unit 32 detects the positions of the mask reference mark 22m and the pattern hole 22a by recognizing the imaging result obtained by the second camera 19. The workpiece recognition unit 33 detects the position of the workpiece 10 placed on the carrier 9 by performing recognition processing on the imaging result obtained by the first camera 18.

In the alignment processing by the alignment processing unit 31, the pickup 10 is picked up by driving the print stage XYΘ table 3xyθ based on the position of the workpiece 10 detected by the workpiece recognition unit 33 while the workpiece 10 is lifted by the workpiece pickup unit 20. An alignment operation for aligning the carrier holding portion of the printing stage 2 with respect to the workpiece 10 is performed.

The print processing unit 34 controls each unit of the screen printing apparatus 1 to perform a process of executing screen printing on the plurality of workpieces 10 arranged on the carrier 9. The print processing unit 34 controls the control valve 23, the backup lifting mechanism 5a, the printing stage lifting mechanism 3z, the printing stage XYΘ table 3xyθ, the side clamp driving mechanism 7a, the printing stage conveyor 6b, the carry-in conveyor 6a, and the carry-out conveyor 6c. The following processes are executed.

That is, the carrier 9 on which the work 10 to be printed is placed on the printing stage 2, the carrier 9 is held by the carrier holding part including the backup part 5 and the side clamp 7, and the mask plate 22 of the work 10 placed on the carrier 9. The operations such as the positioning of the print head 13, the printing of the paste P onto the work 10 by the print head 13 and the print head moving mechanism 14, and the unloading of the carrier 9 after screen printing are performed.

Next, the screen printing method executed by the screen printing apparatus 1 will be described with reference to FIG. First, in a preparatory stage prior to the execution of the screen printing operation, a mask recognition process is executed. That is, as shown in FIG. 8, the second camera 19 is moved by the camera moving mechanism 16 below the mask plate 22 (arrow b), and the mask reference mark 22m (see FIG. 14) on the mask plate 22 is moved to the second position. An image is taken by the camera 19.

Then, the image recognition result is recognized by the mask recognition unit 32 to detect the position of the mask plate 22 and the arrangement of the pattern holes 22a, and the detection result is stored in the mask pattern position storage unit 35a of the storage unit 35. As a result, the position coordinates of the mask center MC (see FIG. 14) of the mask plate 22 and the orientation of the mask plate 22 in the θ direction are detected and stored. In the following screen printing operation, the workpiece 10 is aligned based on the position information of the mask plate 22 stored in the mask pattern position storage unit 35a.

When the screen printing operation is started, the carrier is first carried in (ST1). That is, as shown in FIG. 9, the printing stage moving mechanism 3 is driven to move the printing stage 2 to the upstream side (arrow c), and the printing stage conveyor 6b is connected to the carry-in conveyor 6a. Next, the printing stage conveyor 6b and the carry-in conveyor 6a are driven, and the carrier 9 on which the workpiece 10 is placed and is in a standby state on the carry-in conveyor 6a in advance is transferred to the print stage conveyor 6b (arrow d). Next, as shown in FIG. 10, the printing stage moving mechanism 3 is driven to move the printing stage 2 to the printing position at the center of the mask plate 22 (arrow e).

Thereafter, carrier retention is executed (ST2). That is, as shown in FIG. 11, the backup lifting mechanism 5 a is driven to raise the backup unit 5 (arrow f), and the carrier 9 is lifted to the printing height level in the printing stage 2 below the mask plate 22. Next, the side clamp drive mechanism 7a (see FIG. 6) is driven, and the carrier 9 is sandwiched and clamped by the side clamp 7. As a result, the carrier 9 is held by the carrier holding unit including the backup unit 5 and the side clamp 7. That is, here, the carrier 9 in which the plurality of workpieces 10 are arranged is held below the mask plate 22 in which the pattern holes 22a for printing are formed (carrier holding step).

Thereafter, the plurality of workpieces 10 on the carrier 9 are aligned in accordance with the arrangement of the pattern holes 22a of the mask plate 22 (alignment process). This alignment process is performed as follows. First, workpiece position detection for detecting the positions of the plurality of workpieces 10 on the carrier 9 is executed (ST3) (work position detection step). That is, as shown in FIG. 12, by moving the camera mounting base 17 along the camera X-axis beam 15 by driving the camera moving mechanism 16, the first is placed above the plurality of workpieces 10 arranged on the carrier 9. The camera 18 is positioned.

Here, as shown in FIG. 13, the first camera 18 is sequentially moved above the workpiece 10 disposed in each of the plurality of workpiece storage recesses 9 a provided in the carrier 9 (arrow g), and the workpiece 10 is moved to the workpiece 10. The two formed workpiece recognition marks 10m (see FIG. 4) are imaged. The image recognition result is recognized by the workpiece recognition unit 33, whereby the positional deviation state of each workpiece 10 is detected.

Next, the workpiece position correction amount calculation is executed (ST4). Here, the work position correction amount will be described with reference to FIG. FIG. 14A shows a plane of the mask plate 22. The mask plate 22 is provided with a mask center MC indicating the center position of the mask surface and a pair of mask reference marks 22m serving as a reference for the position on the mask plate 22. A plurality of sets of pattern holes 22 a corresponding to the arrangement pattern of the electrodes 10 a in the workpiece 10 to be printed are formed in the mask plate 22 corresponding to the number of the workpieces 10 in the carrier 9.

A workpiece outer shape 10 * indicated by a broken-line frame in FIG. 14A indicates the outer shape of the workpiece 10 when the electrode 10a of the workpiece 10 is accurately aligned with the pattern hole 22a, and the pattern center 10 * c. Indicates the center of the workpiece outer shape 10 *. These mask pattern data are acquired in advance at the preparation stage before the work starts, and are stored in the mask pattern position storage unit 35a.

(B) shown in FIG. 14 shows the result of executing the workpiece position detection in this alignment step. That is, in the position detection of the workpiece 10 by the first camera 18 shown in FIG. 13, each workpiece 10 is in a different position shift state depending on the arrangement state on the carrier 9. In this work position detection, by recognizing the position of the pair of work recognition marks 10m in each work 10, the center of the work 10c indicating the center of each work 10 is shifted with respect to the pattern center 10 * c, and in the plane. A rotational position shift θ indicating a shift angle of the workpiece reference direction indicating the direction of the workpiece 10 with respect to the mask reference direction is detected.

Accordingly, in order to screen-print the paste P correctly on the workpieces 10 by bringing a plurality of workpieces 10 arranged on the carrier 9 into contact with the lower surface of the mask plate 22, the workpieces on the carrier 9 described above are used. It is necessary to perform an alignment operation for correcting the center position shift and the rotational position shift of 10. In the work position correction amount calculation in (ST4), the position correction amount necessary to correct the center position deviation and the rotational position deviation is obtained individually for each work 10 by the arithmetic processing function of the alignment processing unit 31.

(C) shown in FIG. 14 shows the arrangement state of the workpieces 10 after the alignment processing in which the positions of the workpieces 10 are individually corrected by applying the workpiece position correction amount thus obtained. That is, in this state, the arrangement of the workpieces 10 and the pattern holes 22a match, the workpiece center 10c of the workpiece 10 matches the pattern center 10 * c of the mask plate 22, and the interval between the workpieces 10 and the workpiece 10 The workpiece reference direction and the mask reference direction of the mask plate 22 coincide with each other.

15A to 15C show an operation of correcting the position of the workpiece 10 on the carrier 9 in the above-described alignment process. Here, the workpiece position detection step for detecting the positions of the plurality of workpieces 10 on the carrier 9 is executed in a lump, and the workpiece position correction amount calculation is further performed. Position correction is performed sequentially for individual workpieces 10.

First, the counter value K is set to K = 0 as an initial value (ST5). Next, when the operation is started, the counter value K is incremented by 1, and K = K + 1 is set (ST6). That is, first, the work 10 (1) is the operation target. Here, it is determined by comparing with the allowable threshold value stored in the storage unit 35 whether or not the correction amount of the workpiece 10 (1) is within the allowable range (ST7). If it is determined that it is within the allowable range, it is determined that there is no need to correct the position of the work 10 (1), and (ST8) and (ST9) are skipped to (ST10). move on.

If it is determined in (ST7) that it is outside the allowable range, the workpiece 10 (1) is picked up (ST8). That is, as shown in FIG. 15A, the workpiece pickup unit 20 is moved above the workpiece 10 (1) disposed on the carrier 9, and the workpiece 10 (1) is sucked and lifted by the suction pad 20 a of the workpiece pickup unit 20. .

Next, the work 10 (1) is aligned (ST9). That is, as shown in FIG. 15B, the position of the backup unit 5 is corrected by driving the printing stage moving mechanism 3 based on the correction amount obtained for the workpiece 10 (1) in the workpiece position detection step, and the picked workpiece 10 is picked up. And the carrier 9 are relatively moved. And the workpiece | work 10 (1) is returned to the workpiece | work storage recessed part 9a of the carrier 9 of the state in which the position was corrected. Next, the workpiece 10 (1) is sucked and held (ST10).

That is, as shown in FIG. 15B, the inside of the through hole 9b is vacuum-sucked through the suction path 5b (arrow h), thereby restraining the workpiece 10 (1) in the workpiece housing recess 9a. If it is determined in (ST7) that the correction amount is within the allowable range, (ST8) and (ST9) are skipped and the process proceeds directly to (ST10).

Then, it is determined whether or not the processing has been completed for all the workpieces 10 (ST11). If there is an unprocessed workpiece 10, the processing returns to (ST6) and the same processing steps are performed while the counter value K is sequentially incremented. Run repeatedly. That is, as shown in FIG. 15C, by executing (ST7) to (ST10) for the workpieces 10 (1) to 10 (4), the backup unit 5 has the data after the alignment shown in (c) of FIG. The carrier 9 in which the plurality of workpieces 10 are arranged is held. At this time, all of the workpieces 10 (1) to 10 (4) are constrained in the workpiece housing recess 9a by vacuum-suctioning the through-hole 9b through the suction channel 5b (arrow i). .

In the above processing flow (ST3) to (ST10) constitute the alignment process described above. This alignment step is detected by a workpiece position detection step for detecting the positions of a plurality of workpieces 10 on the carrier 9, a workpiece pickup step for lifting the workpiece 10 that has finished the workpiece position detection step from the carrier 9, and a workpiece position detection step. The workpiece 10 picked up based on the position of the workpiece 10 and the carrier 9 are relatively moved, and then the workpiece alignment step for returning the workpiece 10 to the carrier 9 is included.

In the present embodiment, the workpiece position detection process is collectively performed on the plurality of workpieces 10 in (ST3), and then the workpiece pickup process and the workpiece alignment process are sequentially performed for each individual workpiece 10. I am doing so. Further, for a workpiece 10 that includes a determination step (ST7) for determining whether or not the position of the workpiece 10 detected in the workpiece position detection step is within the allowable range, and for which the position of the workpiece 10 is determined to be within the allowable range in the determination step, The pickup process and the work alignment process are skipped.

Next, if it is determined in (ST11) that the alignment process has been completed for all the workpieces 10, the workpiece alignment state for checking whether the alignment state of the workpieces 10 arranged in the alignment state on the carrier 9 is correct or not. An inspection is executed (ST12). That is, as shown in FIG. 16, all the workpieces 10 that have finished the alignment process and returned to the workpiece storage recess 9 a of the carrier 9 are sequentially imaged while moving the first camera 18 (arrow k). 10 alignments are inspected. At this time, the work 10 is vacuum-sucked through the through-hole 9b from the suction path 5b (arrow j) and is restrained by the work storage recess 9a.

Then, by comparing the displacement amount detected based on the imaging result with the determination threshold stored in the storage unit 35, it is determined whether or not the workpiece alignment state is acceptable (ST13). If it is determined that the workpiece alignment state is acceptable, the process proceeds to (ST16). On the other hand, when it is determined in (ST13) that the workpiece alignment state is unacceptable, the number of failures is confirmed. If it is determined that the number of failures is less than a predetermined number set in advance, the process returns to (ST4) and the subsequent processing is repeatedly executed. If the number of failures has reached a predetermined number in (ST14), it is determined that some malfunction has occurred and an error is notified (ST15).

In (ST16), in order to align the plurality of aligned workpieces 10 and the mask plate 22, the printing stage 2 provided with the carrier holding portion and the mask plate 22 are relatively moved (alignment process). That is, as shown in FIG. 17, the printing stage moving mechanism 3 is driven, and the printing stage 2 in a state where the carrier 9 on which the aligned work 10 is arranged is received and held by the backup unit 5 is held on the mask plate 22. Align with respect to.

Here, the horizontal position of the printing stage 2 is adjusted by the printing stage XYΘ table 3xyθ to align the electrode 10a of the workpiece 10 with the pattern hole 22a of the mask plate 22, and the printing stage 2 is moved by the printing stage lifting mechanism 3z. The workpiece 10 is raised (arrow m) and brought into contact with the lower surface of the mask plate 22.

Next, the print head 13 is moved to print the paste P on the plurality of works 10 aligned from the upper surface of the mask plate 22 through the pattern holes 22a (printing step) (ST17). In this printing step, first, as shown in FIG. 18A, the print head 13 is positioned at a predetermined squeegee start position, and the squeegee driving unit 13a is driven to either one of the two rear squeegees 13b or the front squeegee 13c (here. In the example shown, the front squeegee 13c) is lowered with respect to the upper surface of the mask plate 22 to which the paste P is supplied (arrow n), and the lower end portion of the front squeegee 13c is brought into sliding contact with the mask plate 22. At this time, the work 10 to be printed is received by the backup unit 5 via the carrier 9 and is in contact with the lower surface of the mask plate 22 while being sandwiched by the side clamps 7.

Next, as shown in FIG. 18B, the print head moving mechanism 14 (see FIGS. 1 and 2) is driven to move the print head 13 together with the print head support beam 12 in the squeezing direction (arrow o). As a result, the front squeegee 13 c slides on the upper surface of the mask plate 22 while filling the pattern holes 22 a formed in the mask plate 22 with the paste P, and the paste P is printed on the electrodes 10 a of the workpiece 10.

Thereafter, plate separation for lowering the printing stage 2 is executed (ST18). That is, as shown in FIG. 19, the printing stage moving mechanism 3 is driven to lower the printing stage 2 (arrow p). Thus, plate separation is performed to separate the printing surface on the upper surface of the workpiece 10 from the lower surface of the mask plate 22. Then, the suction of the workpiece 10 to the carrier 9 is released by releasing the vacuum suction from the suction path 5b in the backup unit 5 of the carrier holding unit (ST19). Next, the backup unit 5 is lowered to release the carrier 9 from the under-supported state. At the same time, the carrier holding is released by releasing the clamping of the carrier 9 by the side clamp 7 (ST20). As a result, the carrier 9 is held on the printing stage conveyor 6b.

Thereafter, carrier unloading is executed (ST21). That is, as shown in FIG. 20, the printing stage moving mechanism 3 is driven to move the printing stage 2 to the downstream side (arrow q), and the printing stage conveyor 6b and the carry-out conveyor 6c are connected. Then, by driving the printing stage conveyor 6b and the carry-out conveyor 6c in this state, the carrier 9 on which a plurality of printed works 10 are arranged is transferred from the printing stage conveyor 6b to the carry-out conveyor 6c (arrow r). Thereby, the screen printing process for the carrier 9 on which the plurality of workpieces 10 are arranged is completed.

As described above, in the screen printing shown in the present embodiment, the plurality of workpieces 10 are held below the mask plate 22 in which the pattern holes 22a for printing are formed, and the plurality of workpieces 10 on the carrier 9 are held. Alignment is performed in accordance with the arrangement of the pattern holes 22a, and an alignment process for relatively moving the carrier holding portion and the mask plate 22 to align the plurality of aligned workpieces 10 and the mask plate 22, and from the upper surface of the mask plate 22 The paste P is printed on the plurality of aligned workpieces 10 through the pattern holes 22a.

As a result, in screen printing in which a carrier 9 on which a plurality of workpieces 10 having different misalignment states are arranged is a work target, misalignment correction is performed for each individual workpiece 10 and the skiing that requires the most work time in the printing operation is performed. Jinging work can be performed collectively for a plurality of workpieces 10. Therefore, it is possible to secure high productivity while correcting the positional deviation of the work 10 placed on the carrier 9 to ensure printing accuracy.

Although the present embodiment has been described above, the present disclosure can be implemented by changing the embodiment as illustrated below without departing from the spirit of the present disclosure.

First, in the present embodiment, the printing stage XYΘ table 3xyθ functions as a workpiece alignment mechanism, but the movement mechanism of the workpiece pickup unit 20 as an alignment mechanism such as the camera X axis movement mechanism 16X and the camera Y axis movement mechanism 16Y. Can function.

Furthermore, the screen printing apparatus 1 may be configured to include a movement mechanism dedicated to the work pickup unit 20. In this case, both the moving mechanism dedicated to the work pickup unit 20 or the printing stage XYΘ table 3xyθ may function as the above-described alignment mechanism.

Furthermore, the work pickup unit 20 may be attached to a cleaning mechanism that cleans the lower surface of the mask plate 22. In this case, the cleaning mechanism may be responsible for all or part of the functions as the alignment mechanism described above.

The screen printing apparatus and the screen printing method of the present disclosure have the effect of ensuring high productivity while correcting the positional deviation of the workpiece placed on the carrier and ensuring printing accuracy, such as a substrate. This is useful in the field of screen printing for printing a paste on a workpiece.

DESCRIPTION OF SYMBOLS 1 Screen printer 2 Printing stage 3 Printing stage moving mechanism 3xyz (theta) Printing stage XYΘ table 5 Backup part 7 Side clamp 9 Carrier 10 Work 10 * Work external shape 10 * C Pattern center 13 Print head 17 Camera mounting base 18 1st camera 19 1st 2 camera 20 Work pickup section 22 Mask plate

Claims (11)

A mask plate having a pattern hole for printing;
A carrier holding part for holding a carrier in which a plurality of workpieces are arranged below the mask plate;
An alignment unit for aligning the plurality of workpieces on the carrier in accordance with the arrangement of the pattern holes;
An alignment mechanism for relatively moving the carrier holding portion and the mask plate in order to align the plurality of aligned workpieces and the mask plate;
A screen printing apparatus comprising: a print head configured to print a paste on the plurality of workpieces aligned from an upper surface of the mask plate through the pattern holes. The alignment portion is
A workpiece position detection unit that detects a position by imaging the plurality of workpieces on the carrier with a camera;
A workpiece pick-up unit for lifting at least one of the plurality of workpieces on the carrier from the carrier;
The workpiece alignment mechanism that relatively moves the workpiece picked up by the workpiece pickup unit and the carrier holding unit based on the position of the workpiece detected by the workpiece position detection unit. Screen printing device. The screen printing apparatus according to claim 2, further comprising a moving mechanism for moving the camera and the work pickup unit in a space between the mask plate and the carrier holding unit. The screen printing apparatus according to claim 2, further comprising a moving member that moves in a space between the mask plate and the carrier holding unit, wherein the camera and the work pickup unit are attached to the moving member. The alignment portion is
A workpiece position detection unit that detects a position by imaging the plurality of workpieces on the carrier with a camera;
A workpiece pick-up unit that lifts at least one of the plurality of workpieces on the carrier from the carrier,
The alignment mechanism is
The screen printing according to claim 1, wherein the screen printing is a workpiece alignment mechanism that relatively moves the workpiece picked up by the workpiece pickup unit and the carrier holding unit based on the position of the workpiece detected by the workpiece position detection unit. apparatus. 2. The screen printing according to claim 1, wherein the carrier holding unit includes a work suction unit that introduces a negative pressure into a through-hole penetrating in a thickness direction of the carrier to restrain the plurality of works on the carrier to the carrier. apparatus. The screen printing apparatus according to claim 6, wherein the workpiece suction unit is configured to be able to select introduction and blocking of negative pressure for each workpiece. A carrier holding step for holding a carrier in which a plurality of works are arranged below a mask plate in which a pattern hole for printing is formed;
An alignment step of aligning the plurality of workpieces on the carrier in accordance with the arrangement of the pattern holes;
An alignment step of relatively moving the carrier holding portion and the mask plate in order to align the plurality of aligned workpieces and the mask plate;
And a printing step of printing a paste on the plurality of workpieces aligned from the upper surface of the mask plate through the pattern holes. The alignment step includes
A workpiece position detecting step for detecting positions of the plurality of workpieces on the carrier;
A workpiece pick-up step for lifting the workpiece after the workpiece position detection step from the carrier;
A workpiece alignment step of relatively moving the workpiece picked up based on the position of the workpiece detected in the workpiece position detection step and the carrier, and then returning the workpiece to the carrier,
The screen printing method according to claim 8, wherein the workpiece position detection step is collectively executed for the plurality of workpieces, and then the workpiece pickup step and the workpiece alignment step are sequentially executed for each workpiece. And a determination step of determining whether the position of the workpiece detected in the workpiece position detection step is within an allowable range,
The screen printing method according to claim 9, wherein the pick-up process and the work alignment process are skipped for the work determined to be within the allowable range in the determination process. 10. The screen printing method according to claim 9, further comprising a workpiece suction step of introducing a negative pressure into a through-hole penetrating the carrier thickness method and restraining the workpiece returned to the carrier in the workpiece alignment step.

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