JP2009137669A - Carrying device and carrying error correction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carrying device for relatively displacing a processed object and at least one processing part for applying a predetermined process to part of the processed object, capable of improving carrying accuracy at low cost. <P>SOLUTION: The carrying device has a surface plate 10. A table 2 on which a processed object 1 is placed and a structure 12 for supporting the processing part 14 are provided on the surface plate 10. A plurality of light sources 6a, 6b are mounted on the table 2. A plurality of light detectors 8a, 8b corresponding to the light sources 6a, 6b, respectively are provided on the surface plate 10. A carrying part 4 carries the table 2 to the Y direction on the surface plate 10, so as to relatively displace the table 2 and the processing part 14. The carrying position of the table 2 is detected on the surface plate 10. Based on signals output by the light detectors 8a, 8b and indicating positional shift of light, displacement of the table 2 in the carrying position is detected. Based on the detected displacement of the table 2, the processing part 14 is displaced on the structure 12 or processing timing is changed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transfer apparatus that relatively moves an object to be processed and one or more processing units that perform predetermined processing on a part of the object to be processed.

  The present invention also relates to a transport error correction method capable of improving transport accuracy when the workpiece and the processing unit are relatively moved by such a transport device.

  In recent years, along with the widespread use of large-screen liquid crystal displays, the manufacturing plant transports a plate-like object to be processed such as a glass substrate and a processing unit that performs a predetermined process on a part of the object to be processed. The device is widely used. By using this type of conveying device, it is possible to process substantially the entire workpiece using a relatively small and inexpensive processing unit. As a method of relatively moving the workpiece and the processing section, the processing section is moved in the X direction while the workpiece is moved in the Y direction, and the processing section is fixed in the X and Y directions by fixing the workpiece. Two methods are typical.

  For example, Patent Document 1 (Japanese Patent Laid-Open No. 9-308978) discloses an apparatus for executing the former method as shown in FIG. This apparatus is generally capable of reciprocating in the Y direction on the surface plate 122 placed on the XY plane, a pair of guides 129 and 129 extending in the Y direction laid on the upper surface of the surface plate 122, and the guides 129 and 129. A table 123 provided on the surface plate 122, a stand 124 installed on the surface plate 122 so as to straddle the guides 129 and 129, and a recording head 125 as a processing unit provided on the stand 124 so as to be reciprocally movable in the X direction. It has.

  On the table 123, a photosensitive material 126 made of a glass dry plate coated with a photosensitive agent is placed as an object to be processed. The table 123 is connected to a Y-axis drive motor 128 via a synchronous belt 127 and reciprocates in the Y direction by being guided by a pair of guides 129 extending in the Y direction.

  The recording head 125 is connected to an X-axis drive motor 135 via a ball screw 134 and reciprocates in the X direction by driving the X-axis drive motor 135. The position of the recording head 125 in the X direction is measured by an X-axis length measuring device (not shown). The recording head 125 is provided with an optical system 136 for recording an image on the photosensitive material 126.

  Further, a laser light source 133 for measuring a movement error is attached to the lower edge of the table 123. On the other hand, a CCD 137 that receives the laser beam 101 emitted from the laser light source 133 is mounted on the surface plate 122 below the table 123.

In operation, first, the laser light source 133 is turned on, and the laser beam 101 is emitted in the Y direction. In this state, the table 123 is moved in the Y direction, and the position of the laser beam 101 is measured by the CCD 137. Then, the position data of the laser beam 101 measured by the CCD 137 and the Y coordinate value data of the table 123 measured by the Y-axis length measuring device (not shown) are associated with each other and stored in the control unit (not shown). To do. Thereby, the movement error accompanying the movement of the table 123 in the Y direction is measured. The accuracy is improved by using the movement error recorded here for control.
Japanese Patent Laid-Open No. 9-308978

  However, in the above-described apparatus, of the movement error associated with the movement of the table 123 in the Y direction, the rotational displacement (change in angle with respect to the XY axis) and the horizontal displacement (parallel movement in the X direction) of the table 123 in the XY plane. ) Cannot be distinguished from each other. This problem will be described with reference to FIG. As shown in FIG. 8A, the beam spot 101 a irradiated from the laser light source 133 coincides with the center O of the CCD 137 when there is no movement error of the table 123. FIG. 8B shows a state in which the beam spot 101a on the CCD 137 is displaced to the point 101b (displaced in the X direction) by the table 123 (and hence the laser light source 133 attached thereto) being rotationally displaced by the angle Θ. ing. FIG. 8C shows a state in which the beam spot 101a on the CCD 137 is displaced to the point 101b (displaced in the X direction) due to the horizontal displacement of the table 123 (and hence the laser light source 133 attached thereto). Yes. When FIG. 8B and FIG. 8C are compared, the displacement amount (error amount) that can be detected on the CCD 137 is the same, but the generation factor is different between the rotational displacement and the horizontal displacement. . For this reason, even if it is going to correct | amend a movement error, a control part cannot distinguish whether it is an error by a rotational displacement, or an error by a horizontal displacement, and cannot perform appropriate correction | amendment.

  Accordingly, an object of the present invention is a transfer device that relatively moves an object to be processed and one or more processing units that perform predetermined processing on a part of the object to be processed, and can improve the transfer accuracy at low cost. Is to provide.

In order to solve the above problems, a transport apparatus of the present invention is a transport apparatus that relatively moves a workpiece and one or more processing units that perform predetermined processing on a part of the workpiece,
A surface plate,
A table provided on the surface plate and on which the workpiece is placed;
A structure that is provided on the surface plate and supports the processing unit so as to face the object to be processed;
A plurality of light sources attached to the table;
A plurality of photodetectors provided on the surface plate corresponding to each of the light sources, each of which receives light from the corresponding light source and outputs a signal representing the positional deviation of the light;
A transport unit that transports the table in at least one direction on the surface plate and relatively moves the table and the processing unit;
A transport position detector for detecting the transport position of the table on the surface plate with respect to the one direction;
A displacement detection unit for detecting displacement of the table at the transport position output by the transport position detection unit based on a signal representing the positional deviation of the light output by the plurality of photodetectors;
A displacement correction unit that displaces the processing unit on the structure or changes a processing timing based on the displacement of the table detected by the displacement detection unit is provided.

  In the transport device according to the present invention, the displacement detector is configured to displace the table at the transport position output from the transport position detector based on a signal representing the positional deviation of the light output from the plurality of photodetectors. Is detected. The displacement correction unit displaces the processing unit on the structure or changes the processing timing based on the displacement of the table detected by the displacement detection unit. In this case, it is possible to appropriately correct the transport error caused by the transport unit, and improve the transport accuracy. In other words, since the conveyance accuracy of the conveyance unit may be lowered by that amount, the conveyance unit can be configured at low cost. This advantage is extremely beneficial under recent circumstances where the size of the workpiece is increased, the demand for the conveyance accuracy of the conveyance unit is increased in order to improve the quality of the product, and the conveyance unit is expensive.

  In one embodiment, when the table is at a reference position with respect to the one direction, the light sources and the light sources are arranged so that light from the light sources is incident on a reference position in a light receiving region of the photodetector. The light source mounting mechanism part which can change the light emission direction of the said light source was provided between the tables.

  In the transport apparatus according to this embodiment, for example, immediately before the start of transport by the transport unit, that is, when the table is at a reference position with respect to the one direction, the light from each light source is a reference in the light receiving region of the photodetector. The light emission direction of each light source can be changed by the light source mounting mechanism so as to be incident on the position. Therefore, for example, when the table is at the reference position in the one direction, the light from each of the light sources can be easily adjusted so as to enter the reference position in the light receiving region of the corresponding photodetector. In such a case, the displacement detection unit can easily detect the displacement of the table after the conveyance by the conveyance unit is started.

In the transport device of one embodiment,
Two of the first light source and the second light source are provided as the plurality of light sources,
The first light source and the second light source emit light in opposite directions with respect to the one direction,
The first light detector and the second light detector are provided as the plurality of light detectors corresponding to the first light source and the second light source, respectively.

  In the transport apparatus according to this embodiment, the first light source and the second light source emit light in opposite directions with respect to the one direction. As a result, the movement direction of the light on the photodetector differs depending on whether the displacement of the table at the transport position on the surface plate is horizontal movement (parallel movement in a horizontal plane) or rotational movement. Therefore, the displacement detection unit can distinguish and detect both. Therefore, the displacement correction unit can easily and appropriately correct the displacement of the table.

  In one embodiment, the light source is disposed on both sides of the table.

  In the transport apparatus according to this embodiment, since the light sources are arranged on both sides of the table, the weight balance of the table is eliminated and the posture is stabilized. As a result, the table is less likely to be displaced along with the conveyance by the conveyance unit.

  In the transport apparatus according to an embodiment, each of the photodetectors includes a two-divided photodetector.

  In the transport apparatus of this embodiment, each of the photodetectors is composed of a two-divided photodetector, so that horizontal displacement such as yaw displacement of the table and shift displacement in a direction perpendicular to the transport direction in a horizontal plane is detected in real time. Can be detected. For example, the two-divided photodetector is arranged so that the dividing line extends in the vertical direction, and the light from the light source is set so as to be emitted across each light receiving region of the two-divided photodetector. In this case, the output difference between the light receiving areas arranged in the horizontal direction of the two-divided photodetector corresponds to the horizontal displacement of the table.

  In the transport apparatus according to an embodiment, each of the photodetectors includes a quadrant photodetector.

  In the transport apparatus according to this embodiment, each of the photodetectors is composed of a four-division photodetector. Therefore, the horizontal displacement such as yaw displacement of the table, shift displacement perpendicular to the transport direction in the horizontal plane, and pitching. Vertical displacement such as displacement can be detected in real time. For example, the dividing lines of the four-divided photodetector are arranged so as to extend in the vertical direction and the horizontal direction, respectively, and the light from the light source is set so as to be radiated across each light receiving region of the four-divided photodetector. In such a case, the output difference between the light receiving areas arranged in the horizontal direction among the respective light receiving areas of the quadrant photodetector corresponds to the amount of displacement in the horizontal direction, and the output difference between the light receiving areas arranged in the vertical direction is the vertical direction. Corresponds to the amount of displacement.

  In one embodiment, each of the photodetectors is a CCD line sensor.

  In the transport device of this embodiment, each of the photodetectors is a CCD line sensor. If each CCD line sensor is arranged so as to extend in the horizontal direction, horizontal displacement amounts such as yaw displacement of the table and shift displacement in a direction perpendicular to the conveyance direction in the horizontal plane can be obtained. It can be detected as the amount of displacement of the upper light spot.

  In one embodiment, each of the photodetectors is a CCD area sensor.

  In the transport apparatus of this embodiment, since each of the photodetectors is composed of a CCD area sensor, the amount of displacement in the horizontal direction, such as yaw displacement of the table, shift displacement in a direction perpendicular to the transport direction in the horizontal plane, etc. In addition, a vertical displacement such as a pitching displacement can also be detected as a displacement amount of the light spot on each CCD area sensor.

  The transport apparatus according to an embodiment includes a storage unit that records the transport position of the table output from the position detection unit and the displacement of the table at the transport position and records the information as digital information. And

  When the displacement of the table accompanying the conveyance by the conveyance unit has reproducibility (high repeatability), the displacement of the table can be predicted. Therefore, in the transport apparatus of this embodiment, the transport position of the table output from the position detection unit and the displacement of the table at the transport position are associated with each other and recorded as digital information in the storage unit. As a result, the displacement correction unit can correct the displacement of the table at a higher speed by controlling the processing unit with reference to the recorded content of the storage unit. Furthermore, it is possible to examine secular changes by accumulating data and comparing it with current data. The information on the secular change can be used for predicting the maintenance time of the transfer device.

  In one embodiment, the light source emits light intermittently.

  If the light source is always turned on, there is a possibility of adverse effects such as performance deterioration and shortening of the life due to the influence of heat. Therefore, in the transport device of this embodiment, for example, the light source emits light intermittently as long as the necessary information regarding the displacement of the table can be obtained to such an extent that it does not slow down, that is, considering the transport speed by the transport unit. Let This makes it possible to extend the life of the light source. It also contributes to reduction of power consumption.

In another aspect, the transport device of the present invention is a transport device that relatively moves a workpiece and one or more processing units that perform predetermined processing on a part of the workpiece,
A surface plate,
A table provided on the surface plate and on which the workpiece is placed;
A structure that is provided on the surface plate and supports the processing unit so as to face the object to be processed;
A plurality of light sources attached to the structure;
A plurality of photodetectors provided on the surface plate corresponding to each of the light sources, each receiving light from the corresponding light source and outputting a signal representing a positional deviation of the light;
A transport unit that transports the structure on the surface plate in at least one direction and relatively moves the table and the processing unit;
A transport position detector for detecting the transport position of the structure on the surface plate with respect to the one direction;
A displacement detector that detects displacement of the structure at the transport position output by the transport position detector based on a signal that represents the positional deviation of the light output by the plurality of photodetectors;
A displacement correction unit is provided for displacing the processing unit on the structure or changing a processing timing based on the displacement of the structure detected by the displacement detection unit.

  In the transport apparatus according to the present invention, the displacement detection unit is configured to detect the structure at the transport position output from the transport position detection unit based on a signal indicating the positional deviation of the light output from the plurality of photodetectors. Detect displacement. The displacement correction unit displaces the processing unit on the structure or changes the processing timing based on the displacement of the structure detected by the displacement detection unit. In this case, it is possible to appropriately correct the transport error caused by the transport unit, and improve the transport accuracy. In other words, since the conveyance accuracy of the conveyance unit may be lowered by that amount, the conveyance unit can be configured at low cost. This advantage is extremely beneficial under recent circumstances where the size of the workpiece is increased, the demand for the conveyance accuracy of the conveyance unit is increased in order to improve the quality of the product, and the conveyance unit is expensive.

The transport error correction method of the present invention is a transport error correction method for correcting displacement of the table due to transport when the workpiece and the processing unit are relatively moved by the transport device of the present invention,
Set XY coordinates in the horizontal plane along the upper surface of the surface plate,
Based on the displacement of the table detected by the displacement detector, a displacement Δx in the X-axis direction and a displacement Δy in the Y-axis direction of the target position on the workpiece are obtained,
The processing unit is displaced in the X-axis direction on the structure so as to relatively eliminate the displacement Δx in the X-axis direction, and the processing timing by the processing unit is changed according to the displacement Δy in the Y-axis direction. It is characterized by doing.

  According to the transport error correction method of the present invention, the transport error by the transport unit, here, the displacement Δx in the X-axis direction and the displacement Δy in the Y-axis direction can be corrected appropriately. Therefore, the conveyance accuracy can be improved. In other words, since the conveyance accuracy of the conveyance unit may be lowered by that amount, the conveyance unit can be configured at low cost.

In another aspect, the transport error correction method of the present invention is a transport error correction method for correcting the displacement of the table due to transport when the workpiece and the processing unit are relatively moved by the transport device of one embodiment. And
Set XY coordinates in a horizontal plane along the upper surface of the surface plate, set XYZ coordinates by adding a vertical Z coordinate to the XY coordinates,
Based on the displacement of the table detected by the displacement detector, a displacement Δx in the X-axis direction, a displacement Δy in the Y-axis direction, and a displacement Δz in the Z-axis direction of the target position on the workpiece are obtained,
The processing unit is displaced in the X-axis direction on the structure so as to relatively eliminate the displacement Δx in the X-axis direction, and according to the displacement Δy in the Y-axis direction and the displacement Δz in the Z-axis direction, The processing timing by the processing unit is changed.

  According to the transport error correction method of the present invention, the transport error by the transport unit, here, the displacement Δx in the X-axis direction, the displacement Δy in the Y-axis direction, and the displacement Δz in the Z-axis direction of the target position on the workpiece are determined. Can be corrected appropriately. Therefore, the conveyance accuracy can be improved. In other words, since the conveyance accuracy of the conveyance unit may be lowered by that amount, the conveyance unit can be configured at low cost.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1 and FIG. 2 show the ink-jet droplet applying apparatus according to an embodiment to which the conveying apparatus of the present invention is applied as viewed from above and from the side. Note that the same reference numerals are assigned to the same components.

  This type of ink jet type droplet applying apparatus is suitably used for manufacturing a color filter constituting a liquid crystal panel or the like. A color filter used in a liquid crystal panel or the like means a thin film of each color (red), G (green), and B (blue) formed in a region (pixel) partitioned by a black matrix on a glass substrate. . Such a color filter is a method in which liquid materials of R, G, and B colors are respectively discharged and cured by an inkjet head as a processing unit in a lyophilic region partitioned by a black matrix having liquid repellency ( Manufactured by an inkjet method). The pixels of this color filter are required to have high definition with a width of about 200 μm. In order to achieve this, it is required that the ink ejected from the inkjet head has a landing accuracy of 10 μm or less.

  As shown in FIG. 1 and FIG. 2, the droplet applying apparatus generally includes an anti-vibration table 11, a surface plate 10 placed on an upper surface along the XY plane of the anti-vibration table 11, and an upper surface of the surface plate 10. A pair of guide rails 3a and 3a extending in the Y-axis direction, a table 2 provided so as to be reciprocally movable in the Y-axis direction above the guide rails 3a and 3a, and a guide rail 3a on the surface plate 10, A gate-type structure 12 installed in a manner straddling 3a, a processing unit 14 provided on the gate-type structure 12 so as to be reciprocally movable in the X-axis direction, and a control unit 22 for controlling the entire apparatus. I have.

  A flat glass substrate 1 as an object to be processed is placed on the upper surface of the table 2 along the XY plane. The table 2 is connected to a Y-axis drive motor 4 via a screw shaft 3 or the like. The table 2 is guided by a pair of guide rails 3 a and 3 a extending in the Y-axis direction as it is driven by the Y-axis drive motor 4, and reciprocates in the Y-axis direction. In this example, the Y-axis drive motor 4 and the screw shaft 3 constitute a conveyance unit. An alignment position adjusting mechanism that finely adjusts the position of the table 2 together with the glass substrate 1 in the XY plane will be described later.

  As a driving method of the table 2 in the Y-axis direction, a method of providing a guide shaft and sliding it may be employed.

  In this example, the first laser light source 6a and the second laser light source 6b as light sources are attached to a pair of side surfaces along the Y-axis direction of the table 2 via light source attachment mechanism portions 5a and 5b, respectively. A laser beam 7a that is parallel light is emitted in the + Y-axis direction from the first laser light source 6a on the front side. A laser beam 7b that is parallel light is emitted from the second laser light source 6b in the -Y-axis direction. Since the laser light sources 6a and 6b are arranged on both sides of the table 2, there is no bias in the weight balance of the table 2 and the posture is stabilized. As a result, the table is less likely to be displaced along with the conveyance by the conveyance unit including the Y-axis drive motor 4.

  On the upper surface of the surface plate 10, a first photodetector 8a is mounted via a mounting base 9a at a position to be irradiated with the laser beam 7a emitted from the first laser light source 6a, and the second laser light source 6b is A second photodetector 8b is mounted via a mounting base 9b at a position where the emitted laser beam 7b is to be irradiated. The first photodetector 8a and the second photodetector 8b are each composed of a CCD area sensor having a rectangular light receiving area. The mounting bases 9a and 9b are fixed to the surface plate 10, respectively. Laser beams 7a and 7b emitted from the laser light source 6a and the second laser light source 6b are condensed as beam spots 71a and 71b, respectively, in the light receiving regions of the first photodetector 8a and the second photodetector 8b.

  As a result of such an arrangement, the movement direction of the light on the photodetectors 8a and 8b depends on whether the displacement of the table 2 on the surface plate 10 is horizontal movement (parallel movement in a horizontal plane) or rotational movement. Different. Therefore, it is possible to detect both of them separately, and the displacement of the table 2 can be easily and appropriately corrected.

  When the laser light sources 6a and 6b and the corresponding photodetectors 8a and 8b are attached, initial position adjustment (initial alignment) for aligning the optical axes is performed. As an initial alignment method, the laser light sources 6a and 6b are turned on, the laser light emitting directions of the laser light sources 6a and 6b with respect to the table 2 are changed by the light source mounting mechanisms 5a and 5b, and the beam spots 71a and 71b are detected. It adjusts so that it may be located in the center (more specifically, it means the center of a light-receiving region. The same applies hereinafter) of the devices 8a and 8b. In this case, the range in which the movement amount of the beam spots 71a and 71b can be detected in the photodetectors 8a and 8b is the widest, which is desirable.

  As can be clearly understood from FIG. 2, a slider 19 is provided which is fitted to the screw shaft 3 and can reciprocate in the Y-axis direction. An alignment stage 18 is provided on the slider 19 as an alignment position adjusting mechanism for adjusting the position of the glass substrate 1 in the X-axis direction, the Y-axis direction, and the rotation direction. The above-described table 2 is mounted on the alignment stage 18.

  Alignment marks 17 are formed at a plurality of predetermined locations on the surface of the glass substrate 1 (only one location is shown in FIG. 2 for simplicity). Above the table 2, an alignment camera 16 for imaging the alignment mark 17 is provided.

  When the position of the glass substrate 1 is adjusted, first, a plurality of alignment marks 17 on the surface of the glass substrate 1 are imaged by the alignment camera 16. The output of the alignment camera 16 is sent to the control unit 22 through the wiring 23. The controller 22 drives the above-described alignment stage 18 in the X-axis direction, the Y-axis direction, and the rotation direction in order to move the captured image to a predetermined position. As a result, the glass substrate 1 on the table 2 is arranged at a predetermined position in the XY plane (initialization).

  An encoder detector 21 for detecting the position of the table 2 in the Y direction is attached to the slider 19. On the other hand, a scale 20 is fixedly provided on the surface plate 10. The encoder detector 21 detects the position of the table 2 in the Y-axis direction based on the position information on the scale 20 when the table 2 reciprocates in the Y-axis direction along with the alignment stage 18 and the slider 19 on the surface plate 10. To do. That is, the encoder detector 21 and the scale 20 constitute a conveyance position detection unit. The output of the encoder detector 21 is sent to the control unit 22 through the wiring 23.

  The processing unit 14 is attached to the portal structure 12 via a slider 13 that can reciprocate in the X-axis direction. An inkjet head 14 a protrudes from the bottom of the processing unit 14. The processing unit 14 is moved in the X-axis direction via the slider 13 and is controlled by the control unit 22 so that ink is ejected from the inkjet head 14a in accordance with the ink ejection timing. In response to this control, ink is ejected from the inkjet head 14 a of the processing unit 14 toward the processing target 15 on the glass substrate 1.

  FIG. 3A shows a processing flow in this droplet applying apparatus.

  First, in step S1, the glass substrate 1 carried into the apparatus is mounted on the table 2 and fixed to the table 2 by a known technique such as suction.

  Next, in step S2, the laser light sources 6a and 6b are turned on, and the positions of the beam spots 71a and 71b on the photodetectors 8a and 8b are detected. It is assumed that the initial alignment is completed between the laser light sources 6a and 6b and the photodetectors 8a and 8b.

  Next, in step S3, the alignment stage 18 is driven in the X-axis direction, the Y-axis direction, and the rotation direction to adjust the position of the glass substrate 1 together with the table 2, that is, substrate alignment. In this substrate alignment, the table 2 is driven in the X-axis direction, the Y-axis direction, and the rotation direction. As a result, the glass substrate 1 has a predetermined position and posture. In such a case, the displacement of the table 2 can be easily detected after the transfer to be described later by the Y-axis drive motor 4 is started.

  Along with this substrate alignment, the laser light sources 6 a and 6 b mounted on the table 2 move together with the table 2. As a result, the positions of the beam spots 71a and 71b irradiated from the laser light sources 6a and 6b also move on the photodetectors 8a and 8b. During the substrate alignment, the movement trajectories of the beam spots 71a and 71b are recorded in the storage unit. In addition, when the substrate alignment is performed, data for driving the alignment stage 18 is recorded in the storage unit. The position correction of the beam spots 71a and 71b is performed from the movement locus of the beam spots 71a and 71b recorded here or the alignment stage drive data.

  Next, in step S4, the positions of the beam spots 71a and 71b on the photodetectors 8a and 8b moved by the above-described substrate alignment are detected. The positions of the beam spots 71a and 71b detected at this time are moved by driving the light source mounting mechanisms 5a and 5b to the centers of the light receiving regions of the photodetectors 8a and 8b. This means that the beam spots 71a and 71b are corrected from being shifted from the center positions on the photodetectors 8a and 8b by the substrate alignment described above. At this time, previously recorded movement trajectories of the beam spots 71a and 71b and data for driving the alignment stage 18 may be used. If the beam spots 71a and 71b are not present in the light receiving areas of the photodetectors 8a and 8b, the movement spots of the beam spots 71a and 71b recorded during substrate alignment are analyzed to detect the beam spots 71a and 71b. The information is used to move the container 8 above. That is, by driving the light source mounting mechanisms 5a and 5b so as to reverse the movement trajectories of the beam spots 71a and 71b, the beam spots 71a and 71b are placed on the light receiving regions of the photodetectors 8a and 8b. be able to.

  Next, in step S5, the Y-axis drive motor 4 is driven and the table 2 on which the glass substrate 1 is mounted is conveyed in the Y-axis direction via the screw shaft 3 and the like. Thereby, the glass substrate 1 as a to-be-processed object moves to the Y-axis direction just under the inkjet head 14a of the process part 14. FIG. During the conveyance in the Y-axis direction, as shown in step S6, the position changes of the beam spots 71a and 71b on the photodetectors 8a and 8b are always detected.

  Then, the displacement in the XY plane of the table 2 carrying the glass substrate 1 can be detected by the change in the position of the beam spots 71a and 71b on the photodetectors 8a and 8b. That is, at the start of conveyance, the beam spots 71a and 71b on the photodetectors 8a and 8b are adjusted to be positioned at the centers of the photodetectors 8a and 8b. For this reason, the movement amount of the beam spots 71a and 71b after the start of conveyance corresponds to the movement amount of the table 2. Therefore, the movement amount and posture of the table 2 can be detected. The displacement of the table 2 is generally called yawing, pitching, rolling, horizontal straightness, or vertical straightness. If the beam spots 71a and 71b are not displaced on the photodetectors 8a and 8b, the table 2 is not displaced as described above, and the table 2 is traveling straight along the Y axis.

  If the displacement of the table 2 as described above occurs, the glass substrate 1 mounted on the table 2 is similarly displaced, and the processing target 15 on the glass substrate 1 is also displaced. As a result, the positional relationship between the inkjet head 14a and the processing target 15 on the glass substrate 1 is deviated, and the ink (droplet) ejected from the inkjet head 14a deviates from the processing target 15 on the glass substrate 1. To land on. That is, a landing error occurs.

  Therefore, in step S7, the control unit 22 works as a displacement detection unit, and the processing target 15 and the actual landing location on the glass substrate 1 based on the movement amount of the beam spots 71a and 71b on the photodetectors 8a and 8b. And a driving amount for driving the processing unit 14 is calculated so as to relatively eliminate the landing position deviation amount. .

  In step S8, the driving amount for driving the processing unit 14 is recorded in the storage unit together with the position information of the beam spots 71a and 71b on the photodetectors 8a and 8b and the position information of the table 2. The data recorded here is accumulated and statistical processing is performed. In this case, the result of this statistical process can be used for monitoring the displacement of the table 2. That is, it is possible to monitor deterioration of stage movement accuracy due to aging. Further, if there is no variation in the displacement of the table 2, the processing unit 14 can be driven based on the recorded data.

  Next, in step S9, the processing unit 14 is driven based on the calculated driving amount.

Thereafter, in step S10, the glass substrate 1 is processed by the inkjet head 14a. Specifically, a droplet coating process is performed by the inkjet head 14a.

  Next, how to calculate the amount of positional deviation from the processing target 15 on the substrate will be described with reference to FIGS. In these figures, the glass substrate 1, the laser light sources 6a and 6b, the laser beams 7a and 7b, the photodetectors 8a and 8b, and the beam spots 71a and 71b in FIG. 1 are schematically shown. The centers of the photodetectors 8a and 8b (light receiving areas thereof) are represented as O8a and O8b, respectively.

  As shown in FIG. 4A, after the substrate alignment is performed on the glass substrate 1 carried into the apparatus, the light source mounting mechanism portions 5a and 5b are driven to be mounted on the table 2. The beam spots 71a and 71b by the two laser light sources 6a and 6b are adjusted to the positions of the centers O8a and O8b of the photodetectors 8a and 8b, respectively. From this state, the glass substrate 1 is transported along with the table 2 in the Y-axis direction.

  During the transport in the Y-axis direction, when there is no displacement other than the displacement in the Y-axis direction of the glass substrate 1 accompanying the transport on the XY plane, the state of FIG. 4A is maintained. That is, the state where the beam spots 71a and 71b by the two laser light sources 6a and 6b are respectively present at the centers O8a and O8b of the photodetectors 8a and 8b is maintained.

  On the other hand, during conveyance in the Y-axis direction, it is assumed that the glass substrate 1 has undergone yawing displacement accompanying conveyance on the XY plane. In the example of FIG. 4B, the beam spots 71a and 71b on the photodetectors 8a and 8b cause displacements of xa1 and xb1, respectively.

この式に基づいて、基板上の処理目標１５ａのＵＶ座標は、ＸＹ座標系の座標から算出することができる。逆に、ＵＶ座標からＸＹ座標を算出することも可能である。今後の演算についてはＸＹ座標系で説明する。 Here, as shown in FIG. 5A, two coordinate systems are used. One coordinate system is an XY coordinate system in which the origin is the center O8b of the photodetector 8b of the droplet applying apparatus. Another coordinate system is a UV coordinate system having a point on the glass substrate 1 (a point in the lower left corner in FIG. 5A) 1a as an origin. Here, the origin 1a of the UV coordinate system is a point based on an alignment mark or the like, and is a coordinate system for specifying a processing target. The origin 1a of the glass substrate 1 is (0, 0) in the UV coordinate system, but (x0, y0) in the XY coordinate system. That is, the UV coordinate system is obtained by translating the XY coordinate system by x0 in the X direction and y0 in the Y direction. Assuming that the coordinates of the processing target 15a are expressed as (u, v) in the UV coordinate system and (x, y) in the XY coordinate system, the relationship between them is as follows.

Based on this equation, the UV coordinates of the processing target 15a on the substrate can be calculated from the coordinates in the XY coordinate system. Conversely, XY coordinates can be calculated from UV coordinates. Future calculations will be described in the XY coordinate system.

  Now, the processing target 15a on the table 2 shown in FIG. 4A (its coordinates are (x, y)) is moved to the position 15b (its coordinates are (x ′, y) in FIG. 4B) due to yawing displacement. Let's say '). At this time, it is assumed that the positions of the beam spots 71a and 71b are displaced to xa1 and xb1 on the two photodetectors 8a and 8b, respectively. If there is no yawing displacement, xa1 = 0 and xb1 = 0. Therefore, if the table 2 is moved so that xa1 and xb1 after displacement become 0, the amount of displacement of each point due to yawing can be obtained.

The relationship between the coordinates (x ′, y ′) after yawing displacement and the coordinates (x, y) before yawing will be described. First, from the displacements xa1 and xb1 of the beam spots 71a and 71b and the distance yn between the photodetectors 8a and 8b, the rotation angle θ of the table 2 can be calculated by the following equation (note that atan {} is tan {}. Inverse function.)
θ = atan {(xa1-xb1) / yn}

Next, as shown in FIG. 5B, the beam spot 71b on the photodetector 8b is horizontally moved in the X-axis direction so as to come to the coordinate origin O8b. At this time, the processing target 15b and coordinates (x ′, y ′) change as shown in the following equation.
(X′−xb1, y ′)

この式を（ｘ’、ｙ’）について解くと、次式が成り立つ。

Further, when the rotation of −θ is added, the coordinates (x, y) before the yawing match. That is, the following equation holds.

When this equation is solved for (x ′, y ′), the following equation is established.

Accordingly, the displacement (Δx, Δy) at the processing target 15a and the coordinates (x, y) can be obtained by the following equation.

  The control unit 22 calculates the displacement amount Δx based on the above formula. And the control part 22 works as a displacement correction | amendment part, and calculates the drive amount which should drive the process part 14 so that the displacement amount (DELTA) x may be eliminated relatively. With respect to the X-axis direction, if the processing unit 14 is driven by this driving amount, the landing position deviation caused by the yawing displacement of the table 2 can be corrected.

  Regarding the Y-axis direction, for the displacement Δy caused by yawing of the stage 2, the control unit 22 changes the droplet discharge timing by the inkjet head 14a of the processing unit 14 according to the displacement amount Δy. Thereby, the landing position deviation is corrected in the Y-axis direction.

  In this case, the displacement of the table 2 due to the conveyance in the Y-axis direction, that is, the conveyance error can be appropriately corrected, and the conveyance accuracy can be improved. Conversely, since the conveyance accuracy of the conveyance unit may be lowered by that amount, the conveyance unit including the Y-axis drive motor 4 can be configured at low cost. This advantage is that under the recent situation where the processing object such as the glass substrate 1 is enlarged, the demand for the transport accuracy of the transport unit is increased in order to increase the quality of the product, and the transport unit is expensive. Very beneficial.

  In the processing flow of FIG. 3A described above, “detect the beam movement on the photodetector” in step S6, “calculate the driving amount of the processing unit” in step S7, and “beam spot position, The table position and drive data are recorded.

  One of the utilization methods of these recorded data is to accumulate the beam spot position and drive data for each predetermined table position recorded in step S8 and compare it with the current data. Thereby, the repeat accuracy of table conveyance can be obtained.

  Further, when the repeatability of table conveyance is high, the beam spot position and drive data at a predetermined table position are substantially the same. Therefore, as shown in the processing flow of FIG. 3B, it is not necessary to calculate the driving amount of the processing unit for each table transport (step S7 in FIG. 3A).

  Specifically, steps S11 to S16 in FIG. 3B are performed in the same manner as steps S1 to S6 in FIG. In step S17 in FIG. 3B, the driving amount for driving the processing unit 14 is read from the storage unit, and the processing unit 14 is driven by the driving amount. Thereafter, steps S18 to S19 in FIG. 3B proceed in the same manner as steps S9 to S10 in FIG.

  In this case, the displacement of the table 2 can be corrected at a higher speed. Furthermore, it is possible to examine secular changes by accumulating data and comparing it with current data. The information on the secular change can be used for predicting the maintenance time of the transfer device.

  In the example of FIGS. 4 to 5 described above, the landing position deviation when the yawing displacement of the table 2 occurs is corrected by paying attention to the displacement of the beam spots 71a and 71b on the photodetectors 8a and 8b in the X-axis direction. Explained how to do. In contrast, an example of detecting and correcting not only the yawing displacement of the table 2 but also pitching, horizontal shift, and vertical shift will be described with reference to FIG. In this method, attention is paid to the displacement in the X-axis direction and the Z-axis direction of the beam spots 71a and 71b on the CCD area sensors 8a and 8b as photodetectors.

  6A shows a state of the beam spot 71a condensed on the CCD area sensor 8a, and FIG. 6B shows a state of the beam spot 71a condensed on the CCD area sensor 8b. Yes. In FIGS. 6A and 6B, the light receiving areas of the CCD area sensors 8a and 8b are indicated by rectangular frames. In FIG. 6A, the beam spot 71a is displaced by xa1 in the X-axis direction and za1 in the Z-axis direction. On the other hand, in FIG. 6B, the beam spot 71b is displaced by xb1 in the X-axis direction and zb1 in the Z-axis direction.

  In this example as well, with respect to yawing displacement, the driving amount to drive the processing unit 14 using the displacements xa1 and xb1 in the X-axis direction of the beam spots 71a and 71b, as described with reference to FIGS. Is calculated and corrected.

  Further, by using the displacements za1 and zb1 in the Z-axis direction of the beam spots 71a and 71b and the coordinates (x, y) of the processing target 15 shown in FIG. 6, the Z-axis at the processing target (x, y) is used. The displacement in the direction can be calculated. Specifically, the pitching angle can be calculated by replacing xa1 and xb1 with za1 and zb1, respectively, in the equation for calculating the angle θ in yawing described above. The displacement in the Z-axis direction at the processing target (x, y) can also be calculated by replacing xa1 and xb1 with za1 and zb1, respectively. The method of correcting the displacement in the Z-axis direction calculated here is the processing timing in the control unit 22 so as to relatively eliminate the displacement in the Z-axis direction at the processing target (x, y). Is to change. That is, if the distance between the inkjet head 14a and the glass substrate 1 is reduced by Δz due to the displacement of the table 2, the time to landing is (Δz / v0) when the droplet discharge speed v0 is assumed. ). Therefore, if the transport speed of the table 2 is constant vt, vt · (Δz / v0) is generated as the landing position deviation. In order to correct this, it is only necessary to control the process timing, that is, the droplet discharge timing, to be advanced by the shortened time, that is, (Δz / v0).

  In the above example, the photodetectors 8a and 8b are CCD area sensors. Of course, this is not a limitation. Each photodetector 8a, 8b may comprise a CCD line sensor. In that case, if each CCD line sensor is arranged so as to extend in the horizontal direction, the horizontal displacement amount such as the yaw displacement of the table 2 and the shift displacement in the direction perpendicular to the transport direction in the horizontal plane is calculated. It can be detected as the amount of displacement of the light spot on the line sensor.

  The photodetectors 8a and 8b may be made of a photo detector. Next, how to detect displacements in the X-axis direction and the Z-axis direction when a photodetector is used as a photodetector will be described with reference to FIG.

  FIG. 7A shows an example in which a two-divided photodetector is provided as the photodetector 8a. The light receiving regions 8aa and 8ab of the two-divided photodetector are bilaterally symmetrically divided by a dividing line that passes through the point O8a and extends in the Z-axis direction. A beam spot 71a is irradiated over the light receiving regions 8aa and 8ab. As a result of the table 2 being already driven and moved in the Y-axis direction, the center of the beam spot 71a has moved from the point O8a to the point (xa1, za1). Here, a difference signal (8ab-8aa) which is a difference between the output signals of the light receiving regions 8aa and 8ab is considered. When the beam spot 71a is displaced along the horizontal direction (x-axis direction) on the two-divided photodetector, the output of the difference signal (8ab-8aa) with the movement of the center (xa1, za1) of the beam spot is as shown in FIG. The waveform is as shown in (b). Referring to this waveform, the horizontal displacement amount xa1 can be detected from the difference signal (8ab-8aa) of the two-divided photodetector.

  FIG. 7C shows an example in which a quadrant photodetector is provided as the photodetector 8a. The light receiving areas 8aa, 8ab, 8ac, 8ad of the four-divided photodetector are divided into four square shapes by dividing lines that pass through the point O8a and extend in the X-axis direction and the Z-axis direction. The beam spot 71a is irradiated across these light receiving regions 8aa, 8ab, 8ac, 8ad. As a result of the table 2 being already driven and moved in the Y-axis direction, the center of the beam spot 71a has moved from the point O8a to the point (xa1, za1). Here, a horizontal difference signal {(8ab + 8ad) − (8aa + 8ac)} and a vertical difference signal {(8aa + 8ab) − (8ac + 8ad)} are considered from the output signals of the light receiving areas aa, 8ab, 8ac, and 8ad. . When the beam spot 71a is displaced along the horizontal direction (x-axis direction) on the quadrant photodetector, a horizontal difference signal {(8ab + 8ad) − (8aa + 8ac)} in accordance with the movement of the beam spot center (xa1, za1). The output is the waveform shown in FIG. Referring to this waveform, the horizontal displacement amount xa1 can be detected from the horizontal difference signal {(8ab + 8ad) − (8aa + 8ac)} of the four-divided photodetector. Further, when the beam spot 71a is displaced along the vertical direction (z-axis direction) on the quadrant photodetector, the vertical difference signal {(8aa + 8ab) − (8ac + 8ad) accompanying the movement of the beam spot center (xa1, za1). )} Has the waveform shown in FIG. Referring to this waveform, the vertical displacement amount za1 can be detected from the vertical difference signal {(8aa + 8ab) − (8ac + 8ad)} of the quadrant photodetector.

  In addition, the laser light sources 6a and 6b as light sources are driven intermittently, thereby extending the life of the laser light sources 6a and 6b. It takes a certain amount of time to detect the positions of the beam spots 71a and 71b by the photodetectors 8a and 8b and calculate the driving amount of the processing unit. Moreover, since the mass of movable parts, such as the table 2, is comparatively large, it is thought that there is little sudden displacement. For this reason, it is not necessary to keep the laser light sources 6a and 6b lit at all times. Rather, it is sufficient to emit light at a frequency twice or more the earliest displacement of the table 2 and detect the beam spots 71a and 71b at that time with the photodetectors 8a and 8b.

  In the above example, one processing unit 14 is attached to the portal structure 12, but a plurality of processing units may be attached as a matter of course. If processing points are shared by a plurality of processing units, processing time can be shortened.

  In the above example, the table 2 on which the glass substrate 1 as the object to be processed is driven and moved in the Y-axis direction with respect to the portal structure 12 on which the processing unit 14 is mounted on the surface plate 10. It is configured to do. Of course, this is not a limitation. On the other hand, the gate-type structure 12 on which the processing unit 14 is mounted is driven and moved in the Y-axis direction with respect to the glass substrate 1 as a processing object fixedly placed on the surface plate 10. It may be. In this case, the laser light sources 6 a and 6 b as light sources are attached to the portal structure 12 instead of the table 2. The photodetectors 8a and 8b are arranged on the surface plate 10 so as to receive laser beams from the laser light sources 6a and 6b attached to the portal structure 12, respectively.

  In this embodiment, the conveying device of the present invention is applied to an ink jet type droplet applying device. However, as will be understood by those skilled in the art, the transport device of the present invention is not limited to the droplet applying device, and can be applied to various other applications.

It is a figure which shows the place which looked at the droplet coating device of one Embodiment to which the conveying apparatus of this invention was applied from upper direction. It is a figure which shows the place which looked at the said droplet coating device from the side. (A), (b) is a figure which shows the processing flow which operates the said droplet application apparatus, respectively. (A), (b) is a figure which shows the displacement of the glass substrate on the said droplet coating device. (A), (b) is a figure which shows the displacement of the glass substrate on the said droplet coating device. (A), (b) is a figure which shows the beam spot on the CCD area sensor as a photodetector of the said droplet coating device. (A) is a figure which shows the beam spot on the 2 division | segmentation photodetector as a photodetector of the said droplet coating device, (b) is a figure which shows the output by the 2 division | segmentation photodetector, (c) is a figure of the said droplet coating device. The figure which shows the beam spot on the 4-part photodetector as a photodetector, (d) And (e) is a figure which shows the output by the 4-part photodetector. It is a figure explaining how to detect the movement error of the table in the conventional table movement error measuring device. It is a perspective view which shows the conventional table movement error measuring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Table 4 Y-axis drive motor 5a, 5b Light source attachment mechanism part 6a 1st laser light source 6b 2nd laser light source 7a, 7b Laser beam 8a, 8b Photodetector 9a, 9b Mounting base 10 Surface plate 11 Anti-vibration base 12 Portal structure 13 Slider 14 Processing unit 14a Inkjet head 20 Scale 21 Encoder detector

Claims (13)

A transport device that relatively moves a workpiece and one or more processing units that perform predetermined processing on a part of the workpiece,
A surface plate,
A table provided on the surface plate and on which the workpiece is placed;
A structure that is provided on the surface plate and supports the processing unit so as to face the object to be processed;
A plurality of light sources attached to the table;
A plurality of photodetectors provided on the surface plate corresponding to each of the light sources, each of which receives light from the corresponding light source and outputs a signal representing the positional deviation of the light;
A transport unit that transports the table in at least one direction on the surface plate and relatively moves the table and the processing unit;
A transport position detector for detecting the transport position of the table on the surface plate with respect to the one direction;
A displacement detection unit for detecting displacement of the table at the transport position output by the transport position detection unit based on a signal representing the positional deviation of the light output by the plurality of photodetectors;
A transport apparatus comprising: a displacement correction unit configured to displace the processing unit on the structure or change a processing timing based on the displacement of the table detected by the displacement detection unit. In the conveyance apparatus of Claim 1,
When the table is in the reference position with respect to the one direction, the light source of the light source is placed between the light source and the table so that the light from each light source is incident on the reference position in the light receiving region of the photodetector. A transport apparatus comprising a light source mounting mechanism that can change a light emitting direction. In the conveyance apparatus of Claim 1 or 2,
Two of the first light source and the second light source are provided as the plurality of light sources,
The first light source and the second light source emit light in opposite directions with respect to the one direction,
Corresponding to each of the first light source and the second light source, a transport device comprising a first photodetector and a second photodetector as the plurality of photodetectors. In the conveyance apparatus as described in any one of Claim 1 to 3,
The transport device according to claim 1, wherein the light sources are arranged on both sides of the table. In the conveyance apparatus as described in any one of Claim 1 to 4,
Each of the photodetectors comprises a two-divided photodetector. In the conveyance apparatus as described in any one of Claim 1 to 4,
Each of the photodetectors comprises a quadrant photodetector. In the conveyance apparatus as described in any one of Claim 1 to 4,
Each of the photodetectors comprises a CCD line sensor. In the conveyance apparatus as described in any one of Claim 1 to 4,
Each of the photodetectors comprises a CCD area sensor. In the conveyance apparatus as described in any one of Claim 1-8,
A transport apparatus comprising a storage unit that records the transport position of the table output from the position detection unit and the displacement of the table at the transport position as digital information. In the conveyance apparatus as described in any one of Claim 1-9,
A conveying device characterized in that the light source emits light intermittently. A transport device that relatively moves a workpiece and one or more processing units that perform predetermined processing on a part of the workpiece,
A surface plate,
A table provided on the surface plate and on which the workpiece is placed;
A structure that is provided on the surface plate and supports the processing unit so as to face the object to be processed;
A plurality of light sources attached to the structure;
A plurality of photodetectors provided on the surface plate corresponding to each of the light sources, each of which receives light from the corresponding light source and outputs a signal representing the positional deviation of the light;
A transport unit that transports the structure on the surface plate in at least one direction and relatively moves the table and the processing unit;
A transport position detector for detecting the transport position of the structure on the surface plate with respect to the one direction;
A displacement detector that detects displacement of the structure at the transport position output by the transport position detector based on a signal that represents the positional deviation of the light output by the plurality of photodetectors;
A transport apparatus comprising: a displacement correction unit configured to displace the processing unit on the structure or change a processing timing based on the displacement of the structure detected by the displacement detection unit. A transport error correction method for correcting displacement of the table due to transport when the workpiece and the processing unit are relatively moved by the transport device according to claim 1,
Set XY coordinates in the horizontal plane along the upper surface of the surface plate,
Based on the displacement of the table detected by the displacement detector, the displacement Δx in the X-axis direction and the displacement Δy in the Y-axis direction of the target position on the workpiece are obtained,
The processing unit is displaced in the X-axis direction on the structure so as to relatively eliminate the displacement Δx in the X-axis direction, and the processing timing by the processing unit is changed according to the displacement Δy in the Y-axis direction. A conveyance error correction method characterized by: A transport error correction method for correcting displacement of the table by transport when the workpiece and the processing unit are relatively moved by the transport device according to claim 6,
Set XY coordinates in a horizontal plane along the upper surface of the surface plate, set XYZ coordinates by adding a vertical Z coordinate to the XY coordinates,
Based on the displacement of the table detected by the displacement detector, a displacement Δx in the X-axis direction, a displacement Δy in the Y-axis direction, and a displacement Δz in the Z-axis direction of the target position on the workpiece are obtained,
The processing unit is displaced in the X-axis direction on the structure so as to relatively eliminate the displacement Δx in the X-axis direction, and according to the displacement Δy in the Y-axis direction and the displacement Δz in the Z-axis direction, A transport error correction method, characterized in that the processing timing by the processing unit is changed.

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