JP2009135297A - Detecting device and method of alignment mark - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time required for detecting an alignment mark. <P>SOLUTION: In a detection method of an alignment mark, when detecting an alignment mark M1 of a current substrate 8, a moving device 41 is so controlled that the photographing region of a CCD camera 37 is initially positioned in a mark present region R of a previous substrate 8. When an alignment mark M1 cannot be detected in the mark present region R of the previous substrate 8, the moving device 41 is so controlled that the photographing regions of the CCD camera 37 are sequentially positioned in respective photographing regions, in the order of photographing according to a search table C in a detection range B, with the mark present region R used as a starting point. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for detecting an alignment mark attached to a surface of a substrate.

  As a conventional method for detecting an alignment mark attached to the surface of a substrate, as described in Patent Document 1, a substrate stage and an imaging device are relatively moved in a direction along the surface of the substrate, and an imaging region by the imaging device is set in the substrate. The position of the alignment mark is detected from the image captured by the imaging device.

In the method of detecting an alignment mark described in Patent Document 1, each time an alignment mark on a substrate placed on a substrate stage is detected, the imaging region of the imaging device is placed on the substrate stage in an ideal state of the substrate. It is moved so as to be positioned in the reference imaging area where the center of the imaging area coincides with the position (alignment mark position on the design of the substrate) where the alignment mark should be located when placed. Then, when the alignment mark cannot be detected in the reference imaging area, the imaging area of the imaging apparatus is moved so as to be positioned in each imaging area in a predetermined order starting from the reference imaging area.
JP-A-5-299465

  However, in the alignment mark detection method described in Patent Document 1, the moving order of the imaging regions of the imaging device is fixed in the same order that is determined in advance from the reference imaging region. If the region where the alignment mark is actually located is at the end of the movement order, it takes a long time to detect the alignment mark, and productivity is lowered.

  An object of the present invention is to shorten the detection time of an alignment mark.

  According to the first aspect of the present invention, the substrate stage on which the substrate is placed, the imaging device for imaging the surface of the substrate with the alignment mark, and the substrate stage and the imaging device are relatively moved in a direction along the surface of the substrate. An alignment mark detection device having a moving device that moves an imaging region of the imaging device on the surface of the substrate and a detection device that detects an alignment mark from an image captured by the imaging device. The storage means is set to include a reference imaging area in which the center of the imaging area coincides with a position where the alignment mark should be located when the substrate is placed on the substrate stage in an ideal state, and the reference imaging area. A detection range that determines a moving range of the imaging region by the imaging device that is moved by the moving device within a range having a size corresponding to the plurality of imaging regions. A search table that determines the imaging order of each imaging area in the order in which the plurality of imaging areas in the range move spirally, and a mark existence area that is an imaging area in which an alignment mark is detected in the detection range can be stored and controlled When detecting the alignment mark of the current board, the device controls the moving device so that the imaging area of the imaging device is first positioned in the mark existing area of the previous board. When the mark cannot be detected, the moving device is controlled so that the imaging area of the imaging apparatus is positioned in the respective imaging areas in the imaging order according to the search table in the detection range, starting from the mark existing area. It is what I did.

  The invention according to claim 2 is the alignment mark detection device according to claim 1, wherein the control device detects the first alignment mark of the current substrate. In this case, the moving device is controlled so that the imaging region of the imaging device is first positioned in the mark existing region of the first alignment mark of the previous substrate, and the mark existing region of the first alignment mark of the previous substrate is used. When the first alignment mark cannot be detected, the imaging area of the imaging device is moved so that the mark existing area is used as a starting point and the imaging area is sequentially positioned in the imaging order according to the search table within the detection range. When the apparatus is controlled to detect the second alignment mark on the substrate this time, the first alignment mark is detected based on the first alignment mark detection result. The inclination of the alignment mark is calculated, and the region where the second alignment mark should be located is calculated from the predetermined relative positional relationship between the first and second alignment marks and the above-described inclination of the first alignment mark. The moving device is controlled so that the imaging region of the imaging device is first positioned in this region, and when the second alignment mark cannot be detected in the region where the second alignment mark should be located, the imaging of the imaging device is performed. The moving device is controlled so that the area is sequentially positioned in each imaging area in the imaging order according to the search table in the detection range, starting from the area where the second alignment mark should be located. is there.

  According to a third aspect of the present invention, the substrate stage and the imaging device are relatively moved in the direction along the surface of the substrate, the imaging region by the imaging device is moved on the surface of the substrate, and the alignment mark is detected from the image taken by the imaging device. In the alignment mark detection method to be performed, by the storage means, a reference imaging area in which the center of the imaging area coincides with a position where the alignment mark should be located when the substrate is placed on the substrate stage in an ideal state; A detection range that defines a moving range of the imaging region by the imaging device moved by the moving device within a range having a size corresponding to a plurality of imaging regions set to include the reference imaging region, and a plurality of imaging regions in the detection range. A search table that determines the imaging order of each imaging area in the order of movement in a spiral shape, and the imaging area in which the alignment mark is detected in the detection range Each of the mark existing areas is stored, and when the alignment mark of the current substrate is detected by the control device, the moving device is positioned so that the imaging area of the imaging device is first positioned in the mark existing area of the previous substrate. When the alignment mark cannot be detected in the previous mark existing area of the substrate, the imaging area of the imaging device is set in the imaging order according to the search table within the detection range, starting from this mark existing area. The moving device is controlled so as to be sequentially positioned in each imaging region.

  According to a fourth aspect of the invention, there is provided the alignment mark detection method according to the third aspect, wherein the first and second alignment marks on the substrate are detected, and the first alignment mark of the current substrate is detected by the control device. In this case, the moving device is controlled so that the imaging region of the imaging device is first positioned in the mark existing region of the first alignment mark of the previous substrate, and the mark existing region of the first alignment mark of the previous substrate is used. When the first alignment mark cannot be detected, the imaging area of the imaging device is moved so that the mark existing area is used as a starting point and the imaging area is sequentially positioned in the imaging order according to the search table within the detection range. When the apparatus is controlled to detect the second alignment mark on the substrate this time, the first alignment mark detection result The inclination of the first alignment mark is calculated, and the region where the second alignment mark should be located is calculated from the predetermined relative positional relationship between the first and second alignment marks and the above-described inclination of the first alignment mark. Then, when the moving device is controlled so that the imaging region of the imaging device is first positioned in this region and the second alignment mark cannot be detected in the region where the second alignment mark should be located, The moving device is controlled so that the imaging area is positioned in the respective imaging areas in the imaging order according to the search table in the detection range, starting from the area where the second alignment mark should be located. It is.

  In the present invention, since the imaging region by the imaging device is moved in the spiral imaging order according to the search table within the detection range from the previous mark existing region on the substrate, the alignment mark can be detected in a short time.

  1 is a perspective view showing a paste application device, FIG. 2 is a schematic diagram showing a detection range, FIG. 3 is a schematic diagram showing a search matrix, FIG. 4 is a schematic diagram showing a search table, and FIG. 5 is an imaging order in the detection range. FIG. 6 is a schematic diagram showing an example, FIG. 6 is a schematic diagram showing the entire imaging order in the detection range, FIG. 7 is a flowchart showing the detection procedure of the alignment mark detection device, and FIG. 8 is a block diagram showing the manufacturing process of the liquid crystal display panel.

Embodiments of the present invention will be described below with reference to the drawings.
The liquid crystal display panel manufacturing apparatus 1 includes the following apparatuses as shown in FIG. 8, and the liquid crystal display panel 6 is generally manufactured through the following steps.

  Of the two rectangular transparent glass substrates 7 and 8 to be bonded together in the paste application device 2 in the step (1), a sealant S as a paste is formed in a frame shape with a predetermined thickness around the lower substrate 8. After coating, the liquid crystal L is dropped on the display area inside the sealant S of the lower substrate 8 by the liquid crystal dropping device 3 in the step (2). Alternatively, the sealing agent S may be applied to the upper substrate 7 and the liquid crystal may be dropped onto the display area of the lower substrate 8 that is opposed. Next, in step (3), the substrate bonding apparatus 4 superimposes the upper substrate 7 on the lower substrate 8 in a vacuum chamber (not shown), aligns the upper substrate 7 and the lower substrate 8, and The upper substrate 7 and the lower substrate 8 are bonded together by pressing the substrates 7 and 8 in the vertical direction. In the step (4), the ultraviolet ray irradiating device 5 irradiates the sealing agent S with ultraviolet rays to cure the liquid crystal display panel 6 in which liquid crystal is sealed inside the two substrates 8 and the sealing agent S.

  A paste coating apparatus 2 shown in FIG. 1 is used to apply a sealing agent S as a paste to the periphery of the upper substrate 7 or the lower substrate 8 in the above step (1) in a frame shape.

  First, in FIG. 1, the X axis and the Y axis are orthogonal to each other and extend in the horizontal direction, and the Z axis extends in a direction perpendicular to the X axis and the Y axis. FIG. 1 is a perspective view showing a schematic configuration of a paste coating apparatus 2, and the paste coating apparatus 2 includes a rectangular parallelepiped base 11. As shown in FIG. 1, a Y table 12 is provided on the upper surface of the base 11 so as to be movable along the Y-axis direction (the front-rear direction of the paste application device 2 in FIG. 1). It is driven by a driving means comprising a servo motor 13 that rotates a screw, a nut and a ball screw. A substrate stage 15 is provided on the upper surface of the Y table 12 via a θ rotation mechanism 14. As shown in FIG. 1, the substrate stage 15 can be rotated in a horizontal plane around the Z axis (in FIG. 1, the vertical direction of the paste application device 2) by the θ rotation mechanism 14. The substrate stage 15 has, on its upper surface, a mounting surface 15A for mounting a glass rectangular substrate 8 used for the liquid crystal display panel 6, and means such as vacuum suction (not shown) on the mounting surface 15A. Thus, the substrate 8 is held by suction.

  A gate-shaped support body 20 is provided on the upper surface of the base 11 so as to straddle the Y table 12. A guide rail 21 is fixed to the front surface of the horizontal beam portion of the support 20 along the X-axis direction (left-right direction of the paste application device 2 in FIG. 1) perpendicular to the Y-axis direction. Two left and right X tables 22 are provided on the guide rail 21 so as to be movable in the X-axis direction, and the two X tables 22 are driven by a driving means including a linear motor (not shown). The linear motor includes a magnet provided on the guide rail 21 and a coil provided on the X table 22.

  A Z table 23 is provided on the X table 22 so as to be movable in the Z-axis direction (vertical direction). The Z table 23 is driven by a driving means including a ball screw, a nut, and a servo motor 24 that rotates the ball screw. .

  A discharge device 25 for discharging the sealant S is provided on each Z table 23. The discharge device 25 includes a syringe 27 in which a cylindrical nozzle 26 is detachably attached to the tip, and the syringe 27 to which the nozzle 26 is attached is detachably attached to a holding tool 29 fixed on the Z table 23. Mounted. The syringe 27 is filled with a sealing agent S, each syringe 27 is connected to a pressurized gas source (not shown) via a conduit 30, and an electromagnetic on-off valve 31 is provided between the syringe 27 and the pressurized gas source. An electropneumatic regulator 32 is interposed downstream of the electromagnetic on-off valve 31. The sealing agent S filled in the syringe 27 is pressurized by the pressurized gas from the pressurized gas source and discharged from the nozzle 26 at the tip of the syringe 27.

  On the Z table 23, a first detector comprising a laser displacement meter 28 is integrally attached to the syringe 27. The laser displacement meter 28 measures the distance to the surface of the substrate 8 and mounts the substrate stage 15 thereon. It also functions as a second detector that measures the height of the mounting surface 15A.

  A control device 36 is provided on one side of the base 11 of the coating apparatus. The control device 36 controls the servo motor 13 that drives the Y table 12, the linear motor (not shown) that drives the X table 22, and the servo motor 24 that drives the Z table 23 of the discharge device 25.

  Moreover, the control apparatus 36 controls the electromagnetic on-off valve 31 and the electropneumatic regulator 32 which were interposed by the pipe line 30 between the syringe 27 and a pressurized gas source.

  Further, on each Z table 23, an imaging device including a CCD camera 37 for detecting the position of the substrate 8 placed on the substrate stage 15 is provided.

  A monitor display 38 and an input keyboard 39 are connected to the control device 36.

  Next, an outline of the operation of applying the sealing agent S on the substrate 8 by the paste applying apparatus 2 having the above configuration will be described.

  First, when the substrate 8 is supplied and placed on the placement surface 15A of the substrate stage 15 by a robot (not shown) or the like, an alignment mark attached to the substrate 8 is picked up by the CCD camera 37 as will be described later. A signal is input to the controller 36. The control device 36 detects a positional deviation from a position set in advance by image recognition from the captured image, and controls the X table 22, the Y table 12, and the θ rotation mechanism 14 so that the deviation becomes zero. To do.

  The control device 36 of the paste application device 2 drives the linear motor of the X table 22 and the servo motor 13 of the Y table 12 to move the X table 22 and Y table 12 by a predetermined distance in the horizontal direction from the origin position, and the substrate 8. The nozzle 26 is moved to a standby position above the upper application start point, and the servo motor 24 of the Z table 23 is driven to lower the Z table 23. The control device 36 discharges the sealing agent S from the nozzle 26 at the tip of the syringe 27 of the discharge device 25, relatively moves the nozzle 26 and the substrate 8, and coats and draws a rectangular frame-shaped pattern 33 on the substrate 8. . At this time, the two discharge devices 25 simultaneously apply and draw two patterns 33 arranged in the X-axis direction.

  The laser displacement meter 28 measures the distance to the surface of the substrate 8, and the control device 36 takes in the measured values of the laser displacement meter 28 at regular time intervals, and obtains the tip of the nozzle 26 and the laser displacement meter 28 that have been obtained in advance. Based on the positional relationship, the actual distance (gap) between the tip of the nozzle 26 and the surface of the substrate 8 is calculated. The control device 36 drives the servo motor 24 so that the calculated gap becomes a set value and moves the Z table 23 up and down to adjust the height of the nozzle 26 (gap control). The nozzle 26 and the substrate 8 are moved relative to each other in the XY direction while following the surface. Then, the paste application device 2 applies and draws a pattern 33 having a uniform width and thickness on the substrate 8.

  Further, the control device 36 of the paste application device 2 controls on / off control of the electromagnetic on-off valve 31 provided in the pipe 30 to control the discharge and stop of the sealing agent S, and also controls the electropneumatic regulator 32. The discharge pressure of the sealing agent S is adjusted by adjusting the gas pressure downstream of the electropneumatic regulator 32.

  In this way, the paste application apparatus 2 applies and draws four rectangular frame-shaped patterns 33 on the surface of the substrate 8. In this embodiment, as described below, the first and first patterns attached to the substrate 8 are described. 2 has an alignment mark detection device 40 for detecting two alignment marks M1 and M2.

  The alignment mark detection device 40 includes a substrate stage 15, a CCD camera 37 (imaging device), a moving device 41 including an X table 22, a Y table 12, and a θ rotation mechanism 14, a detection unit 42, a storage unit 43, And a control device 36. In the present embodiment, the control device 36 serves as both the detection means 42 and the storage means 43.

  The substrate stage 15 places the substrate 8 thereon. The CCD camera 37 images the surface of the substrate 8 to which the first and second alignment marks M1 and M2 are attached for each predetermined imaging region (camera viewing range). The moving device 41 relatively moves the substrate stage 15 and the CCD camera 37 in the direction along the surface of the substrate 8, and moves the imaging area by the CCD camera 37 on the surface of the substrate 8 in the X-axis direction and the Y-axis direction. The detecting means 42 detects the positions of the first and second alignment marks M1 and M2 from the image captured by the CCD camera 37.

  The storage unit 43 stores the reference imaging area A, the detection range B, the search table C, and the mark existence area R.

  The reference imaging area A is an area where the centers of the left and right CCD cameras 37 coincide with the positions where the alignment marks M1 and M2 should be located when the substrate 8 is placed on the substrate stage 15 in an ideal state. Say.

  As shown in FIG. 2, the detection range B is a range having a size corresponding to a plurality of imaging regions N set to include the reference imaging region A, and the movement of the imaging region by the CCD camera 37 moved by the moving device 41. Define the scope. In FIG. 2, each small square indicates an imaging area by the CCD camera 37, and an area (0, 0) is a reference imaging area A. The detection range B is not limited in hardware, but is limited in software. When searching for the alignment marks M 1 and M 2, the imaging area of the CCD camera 37 is restricted from moving beyond the detection range B.

  In accordance with the search matrix shown in FIG. 3, the search table C sets the imaging order of each imaging region N in the order in which the plurality of imaging regions N in the detection range B are spirally moved as indicated by arrows (→) in FIG. 4. Determine.

  The mark presence area R is detected within the detection range B as a result of the detection of the alignment mark from the image captured by the CCD camera 37, for example, (1, 1, in the detection range B of FIG. 2 where the alignment mark M1 is detected. -1).

  When the first alignment mark M1 is detected by the CCD camera 37 of the first substrate 8 in the same lot, the control device 36 stores the (0,0) of the search table C in the reference imaging area A (0,0) of the detection range B. ), The imaging order by the CCD camera 37 is determined in the spiral order determined by the search table C, and the imaging area of the CCD camera 37 is positioned in this order, starting from the reference imaging area A (0, 0). 41 is controlled.

  The control device 36 determines the imaging order of the first and second alignment marks M1 and M2 of the second and subsequent substrates 8 in the same lot in the following order. The first alignment mark M1 is imaged by the left CCD camera 37, and the second alignment mark M2 is imaged by the right CCD camera 37.

(Detection of the first alignment mark M1)
(1) When the CCD camera 37 detects the first alignment mark M1 of the substrate 8 this time, the imaging region of the CCD camera 37 is first in the mark existing region R of the first alignment mark M1 of the previous substrate 8. The moving device 41 is controlled to be positioned at the position.

  (2) When the first alignment mark M1 cannot be detected by the CCD camera 37 in the mark existence region R of the first alignment mark M1 of the previous substrate 8 of (1) described above, the imaging region of the CCD camera 37 is The moving device 41 is controlled so that the mark presence region R is set as a starting point, and the imaging regions N are sequentially positioned in the imaging order according to the search table C in the detection range B.

  That is, as shown in FIG. 5, (0,0) of the search table C is superimposed on the mark existence region R (detection range B (1, -1)) of the first alignment mark M1 of the previous substrate 8. Using the mark presence region R as a starting point, the imaging order by the CCD camera 37 is determined in the spiral order determined by the search table C, and the moving device 41 is controlled so that the imaging region of the CCD camera 37 is positioned in this order. When the imaging field of view of the CCD camera 37 is moved in the order of the search table C, the imaging field of view deviates from the detection range B after (2, 1) in the coordinates of the detection range B in FIG. Therefore, the imaging field of view jumps to the position where the imaging field of view next falls within the detection range B in the order of the search table C ((−1, −2 in coordinates of the detection range B)), and the imaging field of view is moved in order from there. Even if it is (2,2) in the coordinates of the detection range B, it jumps to (-2, -2) in the same way.

(Detection of second alignment mark M2)
(1) When the CCD camera 37 detects the second alignment mark M2 on the substrate 8 this time, the inclination of the first alignment mark M1 (for example, the cross-shaped alignment mark M1) is detected from the detection result of the first alignment mark M1. Is calculated from the relative positional relationship between the first and second alignment marks M1 and M2 determined in advance in the design stage of the substrate 8 and the above-described inclination of the first alignment mark M1. A predicted mark area E where the alignment mark M2 should be located is calculated, and the moving device 41 is controlled so that the imaging area of the CCD camera 37 is first positioned in the predicted mark area E.

  (2) When the second alignment mark M2 cannot be detected by the CCD camera 37 in the expected mark area E where the second alignment mark M2 in (1) is located, the imaging area of the CCD camera 37 is The moving device 41 is controlled so that the predicted mark area E where the second alignment mark M2 should be located is a starting point, and the imaging area N is sequentially positioned in the imaging order according to the search table C within the detection range B. .

  When the detection range B is composed of N × N (for example, 5 × 5) imaging regions, the search matrix of the search table C is imaging region (2 × N−1) × (2 × N −1) (for example, 9 × 9). In FIG. 6, when a detection range B composed of 5 × 5 imaging areas is adopted, 5 × 5 examples of imaging by the CCD camera 37 according to the mark existence area R of the first alignment mark M1 of the previous substrate 8 are adopted. Indicates that there can be an order. An imaging region N indicated by dots in the detection range B is a mark presence region R, that is, a position where the imaging region of the CCD camera 37 is first positioned in the detection range B. In FIG. 6, illustration of a portion that protrudes from the detection range B of the search table C is omitted, and only the movement order of the imaging region is indicated by an arrow (→).

  Therefore, when the control device 36 detects the first and second alignment marks M1 and M2 using the CCD camera 37, all the imaging regions N within the detection range B are first imaged as shown in FIG. It is determined whether or not (S1). If YES, the movement range of the imaging area of the CCD camera 37 by the moving device 41 is restricted by the detection range B, and the movement order (moving direction) of the imaging area of the CCD camera 37 by the moving device 41 is as described in (1), After determining (S2) as in (2), determining whether the imaging area of the CCD camera 37 is out of the detection range B (S3), moving the imaging area of the CCD camera 37 (S4), and then detecting the detection area. Alignment marks M1 and M2 are detected from the captured images in each imaging region N in B, and recognition processing is performed (S5). If the detection of the alignment marks M1 and M2 is completed (S6: YES), a positional deviation (correction amount) from a preset position is detected, and the moving device 41 is set so that the deviation becomes zero. Control (S7). If the determination in S1 is NO, the apparatus is stopped as an alignment mark recognition error and an alarm is issued to prompt the operator to perform a recovery procedure.

  In an apparatus in which the substrate 8 is automatically supplied to the substrate stage 15 such as the paste coating apparatus 2 using a substrate transport system such as a robot, the alignment marks M1 and M2 of the substrate 8 placed on the substrate stage 15 are detected. In this case, the detection positions of the alignment marks M1 and M2 are caused by the position where the substrate transport system places the substrate 8 on the substrate stage 15, the displacement of the marking positions of the alignment marks M1 and M2 on the substrate 8, and the like. There is a tendency to shift in a certain direction for each lot.

  For this reason, according to the alignment mark detection device 40 described above, the imaging area by the CCD camera 37 is changed from the previous mark existence area R of the substrate 8 in the spiral imaging order according to the search table C within the detection range B. Therefore, the alignment marks M1 and M2 can be detected with a high probability in a short time.

  In the above embodiment, the alignment mark detection device 40 is applied to the paste application device 2, but the present invention is not limited to this, and any device that can detect an alignment mark can be applied. is there.

FIG. 1 is a perspective view showing a paste coating apparatus. FIG. 2 is a schematic diagram showing a detection range. FIG. 3 is a schematic diagram showing a search matrix. FIG. 4 is a schematic diagram showing a search table. FIG. 5 is a schematic diagram illustrating an example of an imaging order in the detection range. FIG. 6 is a schematic diagram showing the entire imaging order in the detection range. FIG. 7 is a flowchart showing a detection procedure of the alignment mark detection apparatus. FIG. 8 is a block diagram showing a manufacturing process of the liquid crystal display panel.

Explanation of symbols

8 Substrate 15 Substrate stage 36 Control device 37 CCD camera (imaging device)
40 Alignment mark detection device 41 Moving device 42 Detection means 43 Storage means A Reference imaging area B Detection range C Search table R Mark existence area E Expected mark area M1, M2 Alignment mark

Claims (4)

A substrate stage on which the substrate is placed;
An imaging device for imaging the surface of the substrate with an alignment mark;
A relative movement of the substrate stage and the imaging device in a direction along the surface of the substrate, and a moving device for moving an imaging region by the imaging device on the surface of the substrate;
In an alignment mark detection apparatus having detection means for detecting an alignment mark from an image captured by an imaging apparatus,
Having a storage means and a control device;
The storage means
A reference imaging area where the center of the imaging area coincides with the position where the alignment mark should be located when the substrate is placed on the substrate stage in an ideal state;
A detection range that determines a moving range of the imaging region by the imaging device that the moving device moves in a range having a size corresponding to a plurality of imaging regions set to include the reference imaging region;
A search table for determining the imaging order of each imaging area in the order of moving the plurality of imaging areas in the detection range in a spiral shape;
Each of the mark existing area, which is an imaging area where the alignment mark is detected in the detection range, can be stored,
The control device
When detecting the alignment mark of the current board, the moving device is controlled so that the imaging area of the imaging apparatus is first positioned in the mark existing area of the previous board,
When the alignment mark cannot be detected in the mark existing area of the previous substrate, the imaging area of the imaging device is set to each imaging area in the imaging order according to the search table within the detection range, starting from this mark existing area. An alignment mark detecting device, wherein the moving device is controlled so as to be positioned sequentially. The alignment mark detection apparatus according to claim 1, wherein the first and second alignment marks on the substrate are detected.
The control device
When detecting the first alignment mark of the current substrate, the moving device is controlled so that the imaging region of the imaging device is first positioned in the mark existing region of the first alignment mark of the previous substrate,
When the first alignment mark cannot be detected in the mark existing area of the first alignment mark on the previous substrate, the imaging area of the imaging device is searched from the mark existing area as a starting point and within the detection range. Control the moving device to position each imaging region in order in the imaging order according to the table,
When detecting the second alignment mark on the substrate this time, the inclination of the first alignment mark is calculated from the detection result of the first alignment mark, and a predetermined relative position between the first and second alignment marks is calculated. From the relationship and the above-described inclination of the first alignment mark, calculate a region where the second alignment mark should be located, and control the moving device to position the imaging region of the imaging device first in this region,
When the second alignment mark cannot be detected in the area where the second alignment mark should be located, the imaging area of the imaging device is set as the starting point, and the area where the second alignment mark should be located, and An alignment mark detection device that controls the moving device to sequentially position each imaging region in the imaging order according to the search table within the detection range. Relative movement of the substrate stage and the imaging device in the direction along the surface of the substrate, moving the imaging region by the imaging device on the surface of the substrate,
In an alignment mark detection method for detecting an alignment mark from an image captured by an imaging device,
By storage means
A reference imaging area where the center of the imaging area coincides with the position where the alignment mark should be located when the substrate is placed on the substrate stage in an ideal state;
A detection range that determines a moving range of the imaging region by the imaging device that the moving device moves in a range having a size corresponding to a plurality of imaging regions set to include the reference imaging region;
A search table for determining the imaging order of each imaging area in the order of moving the plurality of imaging areas in the detection range in a spiral shape;
A mark existence area that is an imaging area in which the alignment mark is detected in the detection range, respectively,
By control device
When detecting the alignment mark of the current board, the moving device is controlled so that the imaging area of the imaging apparatus is first positioned in the mark existing area of the previous board,
When the alignment mark cannot be detected in the mark existing area of the previous substrate, the imaging area of the imaging device is set to each imaging area in the imaging order according to the search table within the detection range, starting from this mark existing area. A method of detecting an alignment mark, wherein the moving device is controlled so as to be positioned in order. The alignment mark detection method according to claim 3, wherein the first and second alignment marks on the substrate are detected.
By control device
When detecting the first alignment mark of the current substrate, the moving device is controlled so that the imaging region of the imaging device is first positioned in the mark existing region of the first alignment mark of the previous substrate,
When the first alignment mark cannot be detected in the mark existing area of the first alignment mark on the previous substrate, the imaging area of the imaging device is searched from the mark existing area as a starting point and within the detection range. Control the moving device to position each imaging region in order in the imaging order according to the table,
When detecting the second alignment mark on the substrate this time, the inclination of the first alignment mark is calculated from the detection result of the first alignment mark, and a predetermined relative position between the first and second alignment marks is calculated. From the relationship and the above-described inclination of the first alignment mark, calculate a region where the second alignment mark should be located, and control the moving device to position the imaging region of the imaging device first in this region,
When the second alignment mark cannot be detected in the area where the second alignment mark should be located, the imaging area of the imaging device is set as the starting point, and the area where the second alignment mark should be located, and An alignment mark detection method for controlling a moving device so as to sequentially position each imaging region in an imaging order according to a search table within a detection range.

Images