Drawing apparatus and drawing method

Abstract

To accurately perform calibration of a drawing head while preventing an increase in tact time.SOLUTION: With respect to an inspection image group being an assembly of two or more prescribed number of inspection images included in a plurality of inspection images acquired by a calibration camera 53, an evaluation value acquisition part 803 obtains a pattern position being a position of a calibration pattern in each of the inspection images, to obtain a variation evaluation value. The variation evaluation value shows a range of a variation of the prescribed number of pattern positions in the inspection image group. A correction image group setting part 804 sets the inspection image group as a correction image group, when the variation evaluation value is equal to or lower than a prescribed threshold value. A correction information acquisition part 805 obtains correction information used for correction of an irradiation position of light from a drawing head 41, according to the prescribed number of pattern positions of the correction image group. Thereby, calibration of the drawing head 41 can be performed accurately while preventing an increase in tact time.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a technique for irradiating a substrate with light to draw a pattern.

Background Art

[0002] Conventionally, in the drawing of patterns on printed circuit boards, semiconductor substrates, etc. (hereinafter referred to as "substrates"), a drawing apparatus that directly draws a pattern by irradiating a photosensitive material formed on the substrate with modulated light and scanning the irradiated area of the light has been used.

[0003] In such a drawing apparatus, due to the temperature rise of the drawing head and the temperature change around the apparatus with the passage of time from the start of drawing, the irradiation position of the light from the drawing head on the substrate fluctuates, and a positional deviation of the pattern drawn on the substrate may occur. Therefore, in Patent Document 1, a calibration method has been proposed in which the fluctuation data of the irradiation position due to temperature change is acquired in advance, and the irradiation position is corrected according to the measured temperature. However, in indirect calibration using temperature as an index, the calibration accuracy may be insufficient.

[0004] On the other hand, unlike the case where the fluctuation of the irradiation position is indirectly obtained from the temperature as in Patent Document 1, a calibration method is also known in which the light from the drawing head is observed with a camera to directly obtain the fluctuation of the irradiation position. In this case, the stage on which the substrate is placed is moved to position the camera directly below the drawing head for calibration. After the calibration is completed, the stage is moved directly below the drawing head to perform drawing on the substrate. Therefore, a relatively long time is required for one calibration. For this reason, from the viewpoint of shortening the tact time (that is, the time required for the drawing operation on one substrate, also called the cycle time), it is difficult to perform calibration every time the drawing on one substrate is completed. Calibration has been performed every time a predetermined drawing time has elapsed, or every time the drawing on two or more predetermined numbers of substrates has been completed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, in the above-described drawing apparatus, further improvement in drawing position accuracy is desired, and while it is necessary to increase the frequency of calibration, it is also necessary to suppress a decrease in productivity. Further, in the drawing apparatus, improvement in calibration accuracy is also required.

[0007] The present invention has been made in view of the above problems, and an object thereof is to accurately calibrate a drawing head while suppressing an increase in tact time.

Means for Solving the Problems

[0008] Aspect 1 of the present invention is a drawing apparatus that irradiates a substrate with light to draw a pattern, including a stage provided with a substrate holding unit for holding the substrate, a drawing head for irradiating the substrate with modulated light, a main scanning mechanism for relatively moving the stage with respect to the drawing head in a main scanning direction parallel to the upper surface of the substrate, a scale portion located at a calibration position below the drawing head in a state where the stage is positioned at a loading position provided on the stage and where loading and unloading of the substrate to and from the substrate holding unit are performed, a calibration camera that images a calibration pattern irradiated from the drawing head to the scale portion in a state where the scale portion is located at the calibration position, and acquires a plurality of inspection images each including the scale portion and the calibration pattern, an evaluation value acquisition unit that obtains a pattern position which is the position of the calibration pattern in each inspection image for an inspection image group which is a set of two or more predetermined numbers of inspection images included in the plurality of inspection images acquired by the calibration camera, and obtains a variation evaluation value indicating the magnitude of variation of the predetermined number of the pattern positions in the inspection image group, a correction image group setting unit that sets the inspection image group as a correction image group when the variation evaluation value is equal to or less than a predetermined threshold value, a correction information acquisition unit that acquires correction information used for correcting the irradiation position of light from the drawing head based on the predetermined number of the pattern positions of the correction image group, and a drawing control unit that controls the drawing head and the main scanning mechanism based on drawing data and the correction information, and causes the drawing head to perform drawing on the substrate while relatively moving the substrate with respect to the drawing head in the main scanning direction.

[0009] Aspect 2 of the present invention is the drawing apparatus according to Aspect 1, wherein when the variation evaluation value is greater than the threshold value, the calibration camera acquires a new plurality of inspection images after a predetermined waiting time has elapsed since the imaging of the plurality of inspection images was completed, the evaluation value acquisition unit obtains a new variation evaluation value for a new inspection image group that is a set of the predetermined number of inspection images included in the new plurality of inspection images, and the correction image group setting unit sets the new inspection image group as the correction image group when the new variation evaluation value is less than or equal to the threshold value.

[0010] Aspect 3 of the present invention is the drawing apparatus according to Aspect 2, wherein the variation in the predetermined number of pattern positions in the inspection image group is caused by the vibration of the stage that occurs when the substrate is loaded into the substrate holding unit. The waiting time is equal to or longer than the duration of the vibration of the stage when the substrate is loaded into the substrate holding unit.

[0011] Aspect 4 of the present invention is the drawing apparatus according to Aspect 3, wherein when the substrate is loaded into the substrate holding unit, either automatic loading by the loading device or manual loading by the operator is performed. The waiting time is switchable between a first waiting time corresponding to the automatic loading and a second waiting time corresponding to the manual loading and different from the first waiting time.

[0012] Aspect 5 of the present invention is the drawing apparatus according to Aspect 1, wherein the number of the plurality of inspection images acquired by the calibration camera is larger than the number of inspection images included in the inspection image group. When the variation evaluation value is greater than the threshold value, the evaluation value acquisition unit selects a new inspection image group that is a set of the predetermined number of inspection images different from the inspection image group from the plurality of inspection images, obtains a new variation evaluation value for the new inspection image group, and the correction image group setting unit sets the new inspection image group as the correction image group when the new variation evaluation value is less than or equal to the threshold value.

[0013] Aspect 6 of the present invention is the drawing device of Aspect 5, wherein the variation in the predetermined number of pattern positions in the inspection image group is caused by the vibration of the stage that occurs when the substrate is loaded into the substrate holding unit. The time required to acquire the plurality of inspection images by the calibration camera is longer than the duration of the vibration of the stage when the substrate is loaded into the substrate holding unit.

[0014] Aspect 7 of the present invention is the drawing device according to any one of Aspects 1 to 6, including the drawing head, and a plurality of drawing heads each irradiating the substrate with modulated light are arranged in an array direction parallel to the upper surface of the substrate and inclined with respect to the main scanning direction above the scale portion. The calibration camera moves in the array direction in a state where the scale portion is located at the calibration position, and sequentially captures a plurality of calibration patterns respectively irradiated from the plurality of drawing heads to the scale portion, thereby acquiring the plurality of inspection images corresponding to the plurality of drawing heads. The evaluation value acquisition unit obtains the variation evaluation value for each of the plurality of drawing heads. The correction image group setting unit sets the correction image group for each of the plurality of drawing heads. The correction information acquisition unit acquires the correction information for each of the plurality of drawing heads. The drawing control unit controls the plurality of drawing heads and the main scanning mechanism based on the drawing data and the correction information for each of the plurality of drawing heads, thereby performing drawing on the substrate.

[0015] Aspect 8 of the present invention is the drawing device of Aspect 7, wherein the time required from the acquisition of the plurality of inspection images corresponding to the plurality of drawing heads by the calibration camera to the setting of the correction image group for each of the plurality of drawing heads is equal to or less than the time required to unload one substrate from the substrate holding unit and load a new substrate into the substrate holding unit.

[0016] Aspect 9 of the present invention is a drawing device according to Aspect 7 (which may be Aspect 7 or 8). Acquisition of the plurality of inspection images corresponding to each of the plurality of drawing heads by the calibration camera is performed every time a substrate is loaded into the substrate holding unit.

[0017] Aspect 10 of the present invention is a drawing method for performing pattern drawing by irradiating a substrate with light, comprising: a) in a state where a stage provided with a substrate holding unit and a scale unit is located at a loading position where loading and unloading of the substrate to and from the substrate holding unit are performed, imaging a calibration pattern irradiated from the drawing head at the scale unit located at a calibration position below the drawing head, and acquiring a plurality of inspection images each including the scale unit and the calibration pattern; b) for an inspection image group that is a set of two or more predetermined numbers of inspection images included in the plurality of inspection images acquired in step a), obtaining a pattern position that is the position of the calibration pattern in each inspection image, and obtaining a variation evaluation value indicating the magnitude of variation of the predetermined number of the pattern positions in the inspection image group; c) when the variation evaluation value is equal to or less than a predetermined threshold value, setting the inspection image group as a correction image group; d) obtaining correction information used for correcting the irradiation position of light from the drawing head based on the predetermined number of the pattern positions of the correction image group; and e) irradiating the substrate that relatively moves in the main scanning direction with respect to the drawing head with modulated light from the drawing head based on drawing data and the correction information to perform drawing on the substrate.

Advantages of the Invention

[0018] In the present invention, calibration of the drawing head can be accurately performed while suppressing an increase in tact time.

Brief Description of the Drawings

[0019]

Figure 1

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Figure 7D

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Figure 7F

Figure 7G

Figure 7H

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Figure 9

Mode for Carrying Out the Invention

[0020] FIG. 1 is a perspective view showing a drawing apparatus 1 according to an embodiment of the present invention. The drawing apparatus 1 is a direct drawing apparatus that irradiates a photosensitive material on a substrate 9 with spatially modulated substantially beam-shaped light and scans the irradiation region of the light on the substrate 9 to draw a pattern. In FIG. 1, three mutually orthogonal directions are indicated by arrows as the X direction, the Y direction, and the Z direction. In the example shown in FIG. 1, the X direction and the Y direction are horizontal directions perpendicular to each other, and the Z direction is a vertical direction (i.e., the up-down direction). The same applies to other figures.

[0021] The substrate 9 is, for example, a substantially rectangular flat printed circuit board. On the main surface on the (+Z) side of the substrate 9 (hereinafter also referred to as "upper surface 91"), a resist film formed of a photosensitive material is provided on a copper layer. In the drawing apparatus 1, a circuit pattern is drawn (i.e., formed) on the resist film of the substrate 9. Note that the type, shape, etc. of the substrate 9 may be variously changed.

[0022] As shown in FIG. 1, the drawing apparatus 1 includes a stage 21, a stage moving mechanism 22, an alignment unit 3, a drawing unit 4, a calibration unit 5, and a control unit 8. The control unit 8 controls the stage moving mechanism 22, the alignment unit 3, the drawing unit 4, the calibration unit 5, etc.

[0023] The drawing apparatus 1 further includes a housing 6. The housing 6 is, for example, a substantially rectangular parallelepiped exterior member that houses the stage moving mechanism 22, the alignment unit 3, the drawing unit 4, the calibration unit 5, etc. inside. In FIG. 1, the housing 6 is shown by a two-dot chain line, and the internal configuration of the housing 6 is shown by a solid line. The housing 6 is provided with a carry-in port 61 for carrying the substrate 9 into the housing 6, and the carry-in port 61 can be opened and closed by a shutter 62. The carry-in port 61 is provided, for example, at a portion on the (-Y) side of the upper surface of the housing 6. In the example shown in FIG. 1, the carry-in port 61 is located vertically above the stage 21 that is located at the carry-in position to be described later.

[0024] The loading and unloading of the substrate 9 to and from the drawing apparatus 1 through the loading port 61 is performed, for example, by a loading apparatus 95 (see FIG. 7B) that adsorbs and holds the upper surface of the substrate 9. Alternatively, the loading and unloading of the substrate 9 to and from the drawing apparatus 1 may be performed manually by an operator. That is, when the substrate 9 is loaded into the drawing apparatus 1, one of automatic loading by the loading apparatus 95 and manual loading by the operator is selectively performed. The same applies to the unloading of the substrate 9 from the drawing apparatus 1.

[0025] The stage 21 is a substantially rectangular flat plate-shaped member disposed below (i.e., on the (-Z) side) the alignment unit 3 and the drawing unit 4. The stage 21 includes a substrate holding unit 25 that holds the horizontally positioned substrate 9 from below. The substrate holding unit 25 is, for example, a vacuum chuck that adsorbs and holds the lower surface of the substrate 9. The substrate holding unit 25 may have a structure other than a vacuum chuck, and may be, for example, a mechanical chuck. The upper surface 91 of the substrate 9 placed on the substrate holding unit 25 is substantially perpendicular to the Z direction and substantially parallel to the X and Y directions.

[0026] The stage moving mechanism 22 is a moving mechanism that relatively moves the stage 21 in the horizontal direction (i.e., a direction substantially parallel to the upper surface 91 of the substrate 9) with respect to the alignment unit 3 and the drawing unit 4. The stage moving mechanism 22 includes a first moving mechanism 23 and a second moving mechanism 24. The second moving mechanism 24 linearly moves the stage 21 in the X direction along the guide rail. The first moving mechanism 23 linearly moves the stage 21 in the Y direction along the guide rail together with the second moving mechanism 24. The drive sources of the first moving mechanism 23 and the second moving mechanism 24 are, for example, linear servo motors or those in which a motor is attached to a ball screw. The structures of the first moving mechanism 23 and the second moving mechanism 24 may be variously changed.

[0027] In the drawing device 1, a stage rotation mechanism that rotates the stage 21 around a rotation axis extending in the Z direction may be provided. Further, a stage lifting mechanism that moves the stage 21 in the Z direction may be provided in the drawing device 1. As the stage rotation mechanism, for example, a servo motor can be used. As the stage lifting mechanism, for example, a linear servo motor can be used. The structures of the stage rotation mechanism and the stage lifting mechanism may be variously changed.

[0028] The alignment unit 3 includes a plurality (two in the example shown in FIG. 1) of alignment cameras 31 arranged in the X direction. Each alignment camera 31 is supported above the stage 21 and the stage moving mechanism 22 by a support portion 40 provided across the stage 21 and the stage moving mechanism 22. The support portion 40 is a single member provided at one position in the Y direction. In the example shown in FIG. 1, the support portion 40 is a gantry-shaped member (so-called gantry) that straddles the stage 21 and the stage moving mechanism 22.

[0029] In the example shown in FIG. 1, the two alignment cameras 31 are attached to the side surface on the (+Y) side of the support portion 40. Of the two alignment cameras 31, for example, one alignment camera 31 is fixed to the support portion 40, and the other alignment camera 31 is movable in the X direction on the support portion 40. Thereby, the distance in the X direction between the two alignment cameras 31 can be changed. Note that the number of alignment cameras 31 in the alignment unit 3 may be one or three or more.

[0030] Each alignment camera 31 includes an imaging device and an optical system (not shown). Each alignment camera 31 is, for example, an area camera that acquires a two-dimensional image. In each alignment camera 31, the reflected light of the illumination light guided from an illumination light source (not shown) to the upper surface 91 of the substrate 9 is guided to the imaging device via the optical system. The imaging device receives the reflected light from the upper surface 91 of the substrate 9 and acquires an image of a substantially rectangular imaging region. The alignment camera 31 images alignment marks (not shown) provided in advance on the upper surface 91 of the substrate 9. As the illumination light source, various light sources such as an LED (Light Emitting Diode) can be used. Note that the alignment camera 31 may be another type of camera such as a line camera.

[0031] An image including the alignment mark acquired by the alignment camera 31 (hereinafter also referred to as an "alignment image") is sent to the control unit 8 shown in FIG. 1. In the control unit 8, alignment of the substrate 9 (that is, correction of the relative position of the substrate 9 with respect to the drawing head 41 described later) is performed based on the alignment image.

[0032] The drawing unit 4 includes a plurality (six in the example shown in FIG. 1) of drawing heads 41 arranged in the X direction. The plurality of drawing heads 41 have substantially the same structure. Each drawing head 41 includes a spatial light modulator that irradiates modulated (that is, spatially modulated) light downward. Each drawing head 41 is supported above the stage 21 and the stage moving mechanism 22 by the support unit 40 described above. In the example shown in FIG. 1, the six drawing heads 41 are attached to the side surface of the support unit 40 on the (-Y) side. In other words, the six drawing heads 41 are arranged on the side opposite to the two alignment cameras 31 described above with the support unit 40 interposed therebetween in the Y direction. Further in other words, the two alignment cameras 31 are located on the side opposite to the substrate holding unit 25 of the stage 21 located at the loading position described later with the six drawing heads 41 interposed therebetween in the Y direction.

[0033] In the example shown in FIG. 1, the six drawing heads 41 are arranged in a substantially straight line substantially parallel to the X direction. Also, the Z-direction distance between the six drawing heads 41 and the upper surface 91 of the substrate 9 on the stage 21 is substantially the same. In other words, the arrangement direction of the six drawing heads 41 is substantially parallel to the upper surface 91 of the substrate 9 and substantially perpendicular to the Y direction. Further in other words, the positions of the six drawing heads 41 in the Y direction and the Z direction are substantially the same.

[0034] Note that the arrangement direction of the above-described drawing heads 41 may be a direction inclined with respect to the Y direction, and does not necessarily have to be parallel to the X direction. In the drawing unit 4, the plurality of drawing heads 41 do not necessarily have to be arranged in a straight line, and may be arranged, for example, in a staggered pattern. Also, in the drawing unit 4, the number of drawing heads 41 may be one, or may be two or more.

[0035] In the drawing apparatus 1, pattern drawing on the substrate 9 is performed in a so-called multi-pass method. Specifically, while irradiating the upper surface 91 of the substrate 9 with light modulated from the plurality of drawing heads 41 of the drawing unit 4, the substrate 9 is moved in the Y direction by the first moving mechanism 23 of the stage moving mechanism 22 so as to pass below the drawing heads 41. Thereby, the irradiation regions of the light from the plurality of drawing heads 41 are scanned in the Y direction on the substrate 9, and drawing on the substrate 9 is performed. Subsequently, the substrate 9 is stepwise moved in the X direction by the second moving mechanism 24. Then, the movement of the substrate 9 in the Y direction by the first moving mechanism 23 and the irradiation of light from the drawing heads 41 to the substrate 9 in parallel with the movement are performed again, and drawing on the substrate 9 is performed. In the drawing apparatus 1, pattern drawing on the substrate 9 is performed by alternately performing irradiation of light on the substrate 9 moving in the Y direction and stepwise movement of the substrate 9 in the X direction.

[0036] In the following description, the Y direction is also referred to as the "main scanning direction", and the X direction is also referred to as the "sub-scanning direction". The main scanning direction and the sub-scanning direction are directions substantially parallel to the upper surface 91 of the substrate 9. In the stage moving mechanism 22, the first moving mechanism 23 is a main scanning mechanism that relatively moves the stage 21 in the main scanning direction with respect to the drawing head 41. The second moving mechanism 24 is a sub-scanning mechanism that relatively moves the stage 21 in the sub-scanning direction with respect to the drawing head 41. Note that in the drawing apparatus 1, the drawing on the substrate 9 may be performed by a single-pass method (also called a one-pass method) in which the substrate 9 is relatively moved only once in the Y direction with respect to the drawing head 41 to complete the drawing of the pattern on the substrate 9. In this case, during the drawing of the pattern, the sub-scanning of the substrate 9 by the second moving mechanism 24 (that is, the step movement in the X direction) is not performed.

[0037] The calibration unit 5 is provided on the (+Y) side of the substrate holding unit 25 on the stage 21. The calibration unit 5 is used for the calibration of the drawing head 41 (that is, the measurement and correction of the irradiation position of the light from the drawing head 41).

[0038] FIG. 2 is a plan view showing an enlarged view of the vicinity of the calibration unit 5 of the drawing apparatus 1. FIG. 3 is a front view showing the configuration of the calibration unit 5 and the drawing head 41. In FIG. 3, a state in which the drawing head 41 is positioned directly above the calibration unit 5 is shown. In FIG. 3, the internal configuration of the stage 21 and the internal configuration of one drawing head 41 are illustrated. The structure of the other drawing heads 41 is substantially the same as the structure of the one drawing head 41.

[0039] As shown in FIG. 3, the drawing head 41 includes a light source unit 42, an illumination optical system 43, a spatial light modulator 44 (hereinafter also simply referred to as the "light modulator 44"), and a projection optical system 45. The light emitted from the light source unit 42 is guided to the light modulator 44 by the illumination optical system 43, modulated by the light modulator 44, and then guided downward (that is, in the (-Z) direction) of the drawing head 41 by the projection optical system 45.

[0040] The light source unit 42 includes a plurality of light sources that emit light of different wavelengths. In the example shown in FIG. 3, the light source unit 42 includes three light sources 421 to 423. As the light sources 421 to 423, various light sources such as an LD (Laser Diode) can be used. When drawing a pattern on the substrate 9, for example, two or more of the light sources 421 to 423 are used according to the type of photosensitive material on the substrate 9. Note that the number of light sources provided in the light source unit 42 may be one or two, or may be four or more. The light sources provided in the light source unit 42 are not limited to LDs, and various types can be used.

[0041] The illumination optical system 43 and the projection optical system 45 each include optical elements such as a plurality of lenses (not shown). As the light modulator 44, various light modulators such as a DMD (Digital Micro Mirror Device) and a GLV (Grating Light Valve: registered trademark of Silicon Light Machines (Sunnyvale, California)) can be used. The light modulator 44 is not limited to the above example, and various types can be used.

[0042] The calibration unit 5 includes an imaging unit 51 and a scale unit 52. The scale unit 52 is a substantially flat member provided on the stage 21. The scale unit 52 is disposed on the upper surface of the stage 21 and is adjacent to the (+Y) side of the substrate holding unit 25 (that is, disposed in proximity). In the example shown in FIG. 2, the scale unit 52 is a substantially rectangular strip-shaped member that extends substantially parallel to the X direction and has translucency. A number of scales indicating the position in the X direction on the main surface are provided on the main surface on the (+Z) side of the scale unit 52. In other words, the scale unit 52 is a translucent scale member, for example, a substantially transparent glass scale. The scale of the scale unit 52 is, for example, a cross pattern or a pattern of other shapes. Note that the scale unit 52 may be a translucent member.

[0043] The imaging unit 51 is attached inside the stage 21 below the scale unit 52. The imaging unit 51 includes a calibration camera 53 and a camera moving mechanism 54. The calibration camera 53 is disposed facing upward directly below the scale unit 52. The calibration camera 53 is, for example, a digital camera having a CCD (Charged Coupled Devices) or a CMOS (Complementary Metal Oxide Semiconductor) as an imaging element. Note that the type and performance of the calibration camera 53 may be set as appropriate.

[0044] The upper end portion of the calibration camera 53 (i.e., the portion facing the drawing head 41 via the scale unit 52) is subjected to anti-reflection processing. Specifically, for example, an anti-reflection film for reducing the reflectance is attached to the frame of the objective lens of the calibration camera 53. Thereby, it is possible to suppress the unintended imaging of the reflected light from the calibration camera 53 during imaging by the alignment camera 31. Note that the above anti-reflection processing may be performed by various structures and methods other than the anti-reflection film.

[0045] The camera moving mechanism 54 is a moving mechanism that linearly moves the calibration camera 53 along the guide rail in the X direction (i.e., a direction substantially parallel to the arrangement direction of the plurality of drawing heads 41) inside the stage 21. The drive source of the camera moving mechanism 54 is, for example, a linear servo motor or a motor attached to a ball screw. The structure of the camera moving mechanism 54 may be variously changed.

[0046] In the drawing device 1, with a plurality of drawing heads 41 positioned vertically above the scale portion 52 of the calibration unit 5, the calibration camera 53 is moved by the camera moving mechanism 54 and is arranged to be stationary vertically below one of the drawing heads 41 to be calibrated. From the one drawing head 41, a predetermined calibration pattern (i.e., a pattern used for calibrating the drawing head 41) is emitted toward the scale portion 52. The calibration pattern is, for example, a cross-shaped pattern. The shape of the calibration pattern may be variously changed as long as it can calculate the center of gravity position.

[0047] The calibration camera 53 images, from below through the scale portion 52, the irradiation area of the light from the drawing head 41 on the scale portion 52 (i.e., the calibration pattern), together with the above-mentioned scale pre-formed on the scale portion 52. In other words, the calibration camera 53 images the calibration pattern transmitted through the scale portion 52 together with the scale. The image acquired by the calibration camera 53 (hereinafter also referred to as the "inspection image") is sent to the control unit 8 shown in FIG. 1. In the drawing device 1, a plurality of inspection images are acquired by the calibration camera 53 for one drawing head 41 and sent to the control unit 8. The control unit 8 calibrates the one drawing head 41 based on the plurality of inspection images.

[0048] In the drawing device 1, when calibrating other drawing heads 41, the calibration camera 53 is moved in the X direction by the camera moving mechanism 54 and stops vertically below the other drawing head 41. Thereafter, the other drawing heads 41 are calibrated in the same procedure as above.

[0049] FIG. 4 is a diagram showing the configuration of a computer 800 that functions as the control unit 8. The computer 800 has the configuration of a general computer system including a CPU 81, a ROM 82, a RAM 83, a fixed disk 84, a display 85, an input unit 86, a reading device 87, a communication unit 88, a GPU 89, and a bus 80. The CPU 81 performs various arithmetic processes. The GPU 89 performs various arithmetic processes related to image processing. The ROM 82 stores a basic program. The RAM 83 stores various information. The fixed disk 84 stores information. The display 85 is a display unit that displays various information such as images.

[0050] The input unit 86 includes a keyboard 86a and a mouse 86b that receive input from an operator. The reading device 87 reads information from a computer-readable recording medium 871 such as an optical disk, a magnetic disk, a magneto-optical disk, or a memory card. The display 85, the keyboard 86a, the mouse 86b, and the reading device 87 are connected to the bus 80 via an interface I / F. The communication unit 88 transmits and receives signals to and from devices external to the computer 800. The bus 80 is a signal circuit that connects the CPU 81, the GPU 89, the ROM 82, the RAM 83, the fixed disk 84, the display 85, the input unit 86, the reading device 87, and the communication unit 88.

[0051] In the computer 800, a program 872 is read from the recording medium 871 via the reading device 87 in advance and stored in the fixed disk 84. The program 872 may be stored in the fixed disk 84 via a network. The CPU 81 and the GPU 89 execute arithmetic processes while using the RAM 83 and the fixed disk 84 according to the calibration program 872. The CPU 81 and the GPU 89 function as arithmetic units in the computer 800. Other configurations that function as arithmetic units may be adopted in addition to the CPU 81 and the GPU 89.

[0052] FIG. 5 is a block diagram showing the functions of the control unit 8 realized by the computer 800 shown in FIG. 4. In FIG. 5, the configurations other than the control unit 8 are also shown. The control unit 8 includes a storage unit 801, an imaging control unit 802, an evaluation value acquisition unit 803, a correction image group setting unit 804, a correction information acquisition unit 805, an alignment information acquisition unit 806, and a drawing control unit 807. The evaluation value acquisition unit 803 includes a position detection unit 808 and an evaluation value calculation unit 809. The storage unit 801 is realized by a RAM 83, a fixed disk 84, etc. The imaging control unit 802, the evaluation value acquisition unit 803, the correction image group setting unit 804, the correction information acquisition unit 805, the alignment information acquisition unit 806, the drawing control unit 807, the position detection unit 808, and the evaluation value calculation unit 809 are realized by a CPU 81, a GPU 89, a ROM 82, a RAM 83, a fixed disk 84, and their peripheral configurations.

[0053] The storage unit 801 stores in advance various information such as data of the pattern to be drawn on the substrate 9 (i.e., drawing data) and information regarding the calibration of the drawing head 41. The imaging control unit 802 controls the drawing head 41 and the calibration camera 53 to irradiate the calibration pattern stored in advance in the storage unit 801 from the drawing head 41 to the scale unit 52 (see FIGS. 2 and 3), and causes the calibration camera 53 to acquire the above-described inspection image for calibration. The inspection image includes an image of the scale unit 52 and the calibration pattern. In the drawing apparatus 1, a plurality of inspection images are acquired for one drawing head 41. The plurality of inspection images are sent from the calibration camera 53 to the control unit 8 and stored in the storage unit 801.

[0054] The evaluation value acquisition unit 803 obtains a variation evaluation value for a group of inspection images, which is a set of a predetermined number (an integer of 2 or more) of inspection images included in the plurality of inspection images. Specifically, the position detection unit 808 of the evaluation value acquisition unit 803 obtains the position of the calibration pattern in each inspection image of the group of inspection images (hereinafter also referred to as the "pattern position"). In other words, the position detection unit 808 obtains the irradiation position of the light from the drawing head 41 on the scale portion 52 in each inspection image. As described above, since the scale portion 52 is fixed on the stage 21, the relative position of the scale portion 52 with respect to the substrate holding portion 25 is also fixed. Therefore, by detecting the irradiation position of the calibration pattern on the above-mentioned multiple scales of the scale portion 52, the relative position of the irradiation position of the light irradiated from the drawing head 41 with respect to the substrate holding portion 25 can be obtained.

[0055] The evaluation value calculation unit 809 of the evaluation value acquisition unit 803 obtains a variation evaluation value based on the pattern positions in a predetermined number of inspection images of the group of inspection images obtained by the position detection unit 808. The variation evaluation value is a parameter indicating the magnitude of the variation of the predetermined number of pattern positions corresponding to the predetermined number of inspection images. As the variation of the pattern positions in the group of inspection images increases, the variation evaluation value also increases, and as the variation decreases, the variation evaluation value also decreases.

[0056] The correction image group setting unit 804 determines whether to use the above-mentioned group of inspection images as a correction image group for calibration based on the variation evaluation value obtained by the evaluation value acquisition unit 803. Specifically, when the variation evaluation value is less than or equal to a predetermined threshold, the correction image group setting unit 804 determines that the variation of the pattern positions in the group of inspection images is within the allowable range, and sets the group of inspection images as the correction image group. On the other hand, when the variation evaluation value is greater than the above threshold, the correction image group setting unit 804 determines that the variation of the pattern positions in the group of inspection images is greater than the allowable degree. In this case, as will be described later, a new group of inspection images is selected, and based on the variation evaluation value of the new group of inspection images, the correction image group setting unit 804 determines whether to use the new group of inspection images as the correction image group.

[0057] Based on the pattern positions of each inspection image in the correction image group set by the correction image group setting unit 804, the correction information acquisition unit 805 acquires correction information used for calibration of the drawing head 41 (that is, correction of the irradiation position of light from the drawing head 41 on the substrate).

[0058] Based on the image of the above-described alignment mark (hereinafter also referred to as "alignment image") acquired by the alignment camera 31 of the alignment unit 3, the alignment information acquisition unit 806 acquires alignment information used for alignment of the substrate 9 (that is, correction of the relative position of the substrate 9 with respect to the drawing head 41). Specifically, based on the position of the alignment mark in the alignment image, the position of the substrate 9 on the substrate holding unit 25 is obtained, and the deviation amount from the designed position of the substrate 9 on the substrate holding unit 25 is obtained. In other words, the deviation amount from the designed position of the relative position of the substrate 9 with respect to the drawing head 41 is obtained. The alignment information acquisition unit 806 obtains the above-described alignment information for correcting the relative position of the substrate 9 with respect to the drawing head 41 to match the designed position based on the deviation amount. The alignment information is, for example, information for correcting the movement of the substrate 9 by the stage movement mechanism 22 when drawing a pattern on the substrate 9. Alternatively, the alignment information may be information for correcting the drawing data of the pattern drawn on the substrate 9 according to the deviation amount.

[0059] Based on the drawing data stored in the storage unit 801, the correction information of each drawing head 41 obtained by the correction information acquisition unit 805, the alignment information obtained by the alignment information acquisition unit 806, etc., the drawing control unit 807 controls the plurality of drawing heads 41 and the stage movement mechanism 22, thereby relatively moving the substrate 9 with respect to the plurality of drawing heads 41 and causing the plurality of drawing heads 41 to perform drawing on the substrate 9.

[0060] Next, with reference to FIGS. 6 and 7A to 7H, the pattern drawing by the drawing apparatus 1 will be described. FIG. 6 is a diagram showing an example of the flow of pattern drawing on the substrate 9. FIGS. 7A to 7H are front views schematically showing the main configuration of the drawing apparatus 1 in order to explain the operation of the drawing apparatus 1. In FIGS. 7A to 7H, the internal configuration of the stage 21 is also shown by a solid line.

[0061] When drawing on the substrate 9, first, the stage 21 is arranged in a stationary state at the position shown in FIG. 7A. In the following description, the position of the stage 21 in the Y direction shown in FIG. 7A is also referred to as the "loading position". In the state where the stage 21 is located at the loading position, the substrate holding portion 25 is located on the (-Y) side of the plurality of drawing heads 41 and the plurality of alignment cameras 31 attached to the support portion 40 (see FIG. 1). Also, as described above, above the substrate holding portion 25 of the stage 21 located at the loading position, the loading port 61 of the housing 6 is located. The loading port 61 is closed by a shutter 62. On the substrate holding portion 25, a substrate 9 on which the drawing in the drawing apparatus 1 has already been completed is held.

[0062] Subsequently, when the shutter 62 moves, as shown in FIG. 7B, the loading port 61 is opened, and the drawn substrate 9 is automatically carried out by the loading apparatus 95. The loading apparatus 95 adsorbs and holds, for example, the upper surface (i.e., the main surface on the (+Z) side) of the drawn substrate 9. The loading apparatus 95 moves the held substrate 9 upward and carries it out of the housing 6 through the loading port 61.

[0063] When the unloading of the drawn substrate 9 is completed, as shown in FIG. 7C, an undrawn substrate 9 (i.e., a substrate 9 on which drawing by the drawing apparatus 1 is scheduled) is adsorbed and held by the loading apparatus 95 and carried into the housing 6 through the loading port 61. The undrawn substrate 9 is placed on the substrate holding portion 25 of the stage 21 and held by the substrate holding portion 25. Thereafter, the loading apparatus 95 retracts to the outside of the drawing apparatus 1, and as shown in FIG. 7D, the loading port 61 is closed by the shutter 62. Thereby, the loading and unloading process of the substrate 9 is completed.

[0064] The loading / unloading process is an operation related to the unloading and loading of the substrate 9 that is performed while the shutter 62 opens and then closes the loading / unloading port 61. The time required for the loading / unloading process (i.e., the time from when the loading / unloading port 61 opens to when it closes, hereinafter also referred to as the "loading / unloading time") is, for example, about 6 seconds. The loading / unloading time is the time required to unload one substrate 9 from the substrate holding unit 25 and load a new substrate 9 into the substrate holding unit 25. When the unloading and loading of the substrate 9 to / from the drawing apparatus 1 are performed manually by an operator, the loading / unloading time is usually longer than the loading / unloading time by the loading / unloading apparatus 95. For example, the loading / unloading time by manual operation of the operator is about 15 seconds.

[0065] In the drawing apparatus 1, with the stage 21 positioned at the loading position shown in FIGS. 7A to 7D, the scale portion 52 of the calibration unit 5 is positioned directly below the drawing head 41. In the following description, the position of the scale portion 52 in the Y direction shown in FIGS. 7A to 7D is also referred to as the "calibration position". In the drawing apparatus 1, with the stage 21 positioned at the loading position and the scale portion 52 positioned at the calibration position, calibration of a plurality of drawing heads 41 is sequentially performed in parallel with the above-described loading / unloading process of the substrate 9 (step S11). Thereby, correction information used for correcting the light irradiation position from each drawing head 41 is acquired. Calibration of the plurality of drawing heads 41 is completed, for example, within the above-described loading / unloading time (i.e., between when the loading / unloading port 61 opens and when it closes). Details of the calibration of the drawing head 41 will be described later.

[0066] When step S11 (that is, the loading and unloading of the substrate 9 and the calibration of the plurality of drawing heads 41) is completed, the stage 21 is moved in the (+Y) direction by the first moving mechanism 23 of the stage moving mechanism 22. As shown in FIG. 7E, the stage 21 passes below the alignment camera 31 and moves to the standby position shown in FIG. 7F and stops. As shown in FIG. 7E, when the stage 21 passes below the alignment camera 31, an alignment mark (not shown) provided in advance on the substrate 9 on the substrate holding portion 25 is imaged by the alignment camera 31. When imaging the alignment mark, pulsed illumination light (that is, flash) is irradiated from the illumination light source of the alignment unit 3 to the imaging region of the alignment camera 31. Thereby, the alignment mark on the moving substrate 9 is accurately imaged. As described above, in the calibration unit 5 that passes below the alignment camera 31, since the upper end portion of the calibration camera 53 is subjected to antireflection processing, the reflected light of the illumination light by the calibration camera 53 is suppressed or prevented from entering the alignment camera 31.

[0067] An image including the alignment mark acquired by the alignment camera 31 (that is, an alignment image) is sent to the control unit 8 and stored in the storage unit 801 (see FIG. 5). In the alignment information acquisition unit 806, alignment information is obtained based on the alignment image. Then, based on the alignment information, alignment processing of the substrate 9 by the drawing control unit 807 is performed (step S12). In the alignment process, in order to match the position of the substrate 9 with a predetermined design position, for example, the shift of the stage 21 in the X and Y directions (that is, the movement of a minute distance), rotation, or the correction of the drawing data of the pattern drawn on the substrate 9 is performed.

[0068] When the above alignment process is completed, the stage 21 located at the standby position starts to move in the (-Y) direction. In the calibration unit 5, before the stage 21 starts to move in the (-Y) direction, the calibration camera 53 is moved in the X direction and retracts to a retracted position on the (+X) side or (-X) side from directly below the scale unit 52. That is, the retracted position is located on the (+X) side or (-X) side with respect to the position where the scale unit 52 is provided on the stage 21. Thereby, it is possible to suppress or prevent relatively high-intensity light used for pattern drawing from entering the calibration camera 53.

[0069] In the drawing apparatus 1, as shown in FIG. 7G, the substrate 9 held by the substrate holding unit 25 passes below the drawing head 41. Then, based on the above-described drawing data, correction information, etc., the drawing control unit 807 (see FIG. 5) controls each drawing head 41 and the stage movement mechanism 22, so that the substrate 9 on the stage 21 moving in the Y direction below the plurality of drawing heads 41 is irradiated with light modulated from the plurality of drawing heads 41, and a pattern is drawn (step S13).

[0070] In the present embodiment, as described above, since the pattern drawing on the substrate 9 is performed in a multi-pass method, the substrate 9 reciprocating in the Y direction below the drawing head 41 is irradiated with light modulated from the drawing head 41, and a pattern is drawn. Further, when drawing a pattern on the substrate 9, it is preferable that two or more of the three light sources 421 to 423 (see FIG. 3) of the light source unit 42 are used in each drawing head 41. Thereby, it is possible to perform suitable pattern drawing according to the type of the photosensitive material on the substrate 9 and the like.

[0071] When the pattern drawing on the substrate 9 is completed, the stage 21 is moved to the loading position shown in FIG. 7H (step S14). At this time, the calibration camera 53 moves in the X direction from the retracted position and is returned directly below the scale unit 52. Thereby, the pattern drawing on one substrate 9 is completed.

[0072] In the actual drawing apparatus 1, it returns from step S14 to step S11, and steps S11 to S14 are sequentially performed on a plurality of substrates 9, and patterns are drawn. In the drawing apparatus 1, in this way, calibration for each drawing head 41 is performed every time a substrate 9 is loaded into the substrate holding unit 25 (step S11). Thus, even when continuously drawing patterns on a plurality of substrates 9, the accuracy of pattern drawing on the substrate 9 can be maintained at a high level. Further, since calibration for the drawing head 41 is performed in parallel with the loading and unloading of the substrate 9, the time required for the drawing process on a plurality of substrates 9 can be shortened. In other words, in the drawing apparatus 1, calibration of the drawing head 41 can be performed while suppressing an increase in the tact time.

[0073] Next, details of the calibration of the drawing head 41 will be described with reference to FIGS. 8 and 9. FIG. 8 is a diagram showing the flow of calibration by the first calibration method. FIG. 9 is a diagram showing the flow of calibration by the second calibration method. In FIGS. 8 and 9, the flow of calibration for one drawing head 41 is shown respectively. The flow of calibration for other drawing heads 41 is the same as that shown in FIGS. 8 and 9. Hereinafter, first, the first calibration method will be described, and then the second calibration method will be described.

[0074] When calibration of the drawing head 41 is performed by the first calibration method, first, with the scale portion 52 positioned at the calibration position, the calibration camera 53 of the imaging unit 51 is moved in the X direction by the camera moving mechanism 54 (see FIGS. 2 and 3). The calibration camera 53 is disposed vertically below one drawing head 41 that is the calibration target.

[0075] Then, with the calibration camera 53 stationary directly below the drawing head 41, the light source unit 42 and the optical modulator 44 (see FIG. 3) of the drawing head 41 and the like are controlled by the imaging control unit 802, so that the calibration pattern described above is irradiated from the drawing head 41 to the scale unit 52. In the light source unit 42, only one predetermined light source out of the above-described light sources 421 to 423 (see FIG. 3) is used when irradiating the calibration pattern. As a result, the calibration pattern on the scale unit 52 is formed by light of a single wavelength.

[0076] Subsequently, the calibration camera 53 is controlled by the imaging control unit 802 (see FIG. 5), so that the calibration pattern irradiated on the scale unit 52 located at the calibration position is imaged together with the scale of the scale unit 52 to obtain an inspection image. The calibration camera 53 images the calibration pattern irradiated by one drawing head 41 a plurality of times to obtain a plurality of inspection images (step S21). Each of the plurality of inspection images includes an image of the scale unit 52 and the calibration pattern. The plurality of inspection images are sent to the control unit 8 and stored in the storage unit 801 (see FIG. 5). The number of inspection images obtained in step S21 is, for example, five. The number of the inspection images may be variously changed within a range of two or more as long as it is equal to or more than the number of inspection images included in the inspection image group selected in step S22 described later.

[0077] Subsequently, an evaluation value acquisition unit 803 (see FIG. 5) selects an inspection image group, which is a set of two or more predetermined numbers of inspection images, from the plurality of inspection images described above. The predetermined number may be variously changed within a range of two or more as long as it is equal to or less than the number of inspection images acquired in step S21. In the present embodiment, all five inspection images continuously acquired for one drawing device 1 are selected as the inspection image group. In other words, the predetermined number described above is also five, the same as the number of inspection images included in the inspection image group. Then, a position detection unit 808 (see FIG. 5) obtains a pattern position, which is the position of the calibration pattern in each inspection image of the inspection image group (step S22). The pattern position is obtained using various known image processing methods (for example, pattern matching). The predetermined number of pattern positions corresponding to the predetermined number of inspection images described above (five pattern positions in the present embodiment) is sent from the position detection unit 808 to an evaluation value calculation unit 809 (see FIG. 5).

[0078] In the evaluation value calculation unit 809, a variation evaluation value, which is a parameter indicating the magnitude of the variation in the predetermined number of pattern positions in the inspection image group, is obtained from the predetermined number of pattern positions obtained by the position detection unit 808 (step S23). As described above, the variation evaluation value increases as the variation in the pattern positions in the inspection image group increases, and decreases as the variation decreases. The variation evaluation value is, for example, the standard deviation or variance of the predetermined number of pattern positions. Note that the variation evaluation value is not limited to the standard deviation and variance, and may be other parameters indicating the magnitude of the variation (that is, the degree of variation) in the predetermined number of pattern positions. The variation evaluation value obtained by the evaluation value calculation unit 809 is sent to a correction image group setting unit 804 (see FIG. 5).

[0079] In the correction image group setting unit 804, the above variation evaluation value is compared with a predetermined threshold value prestored in the storage unit 801 (step S24). When the variation evaluation value is equal to or less than the threshold value, it is determined that the variation in the pattern positions in the inspection image group is within the allowable range, and the inspection image group is set as a correction image group suitable for the calibration of the drawing head 41 (step S25).

[0080] The threshold value is determined in advance based on, for example, the resolution of the calibration camera 53 and is prestored in the storage unit 801. In the present embodiment, the threshold value is determined based on the following criteria. For example, if the resolution of the calibration camera 53 is 1 μm and the calibration of the drawing head 41 is performed with an accuracy equal to or lower than the resolution, if the variation in the pattern positions in the inspection image group is about 1 μm, it is due to the blur caused by the resolution, and it is determined that the inspection image group is appropriate (i.e., usable) as a correction image group. On the other hand, when the variation is significantly larger than 1 μm, it is highly likely that the variation is caused by other factors (e.g., disturbances such as vibrations of the stage 21), and thus it is determined that the inspection image group is inappropriate as a correction image group.

[0081] In step S24, if the above-described variation evaluation value is greater than the threshold value, it is determined that the variation in the pattern positions in the inspection image group is outside the allowable range, and it is determined that the inspection image group is inappropriate as the correction image group. The variation in the pattern positions when the variation evaluation value becomes greater than the threshold value is typically caused by the vibration of the stage 21 when the substrate 9 carried into the drawing apparatus 1 is placed on the substrate holding portion 25. In other words, the variation in the pattern positions is caused by the vibration of the stage 21 when the substrate 9 is carried into the substrate holding portion 25 by the carrying-in apparatus 95. That is, when the imaging timing of one or more inspection images included in the inspection image group overlaps with the time during which the vibration of the stage 21 occurs, the above-described pattern positions vary greatly, and the possibility that the variation evaluation value becomes greater than the threshold value increases. The vibration of the stage 21 is large, for example, in the Y direction, which is the moving direction by the first moving mechanism 23 using a linear servo motor. The vibration of the stage 21 continues for a short time of, for example, 0.5 seconds or less and then disappears.

[0082] In the drawing apparatus 1, when it is determined in step S24 that the variation evaluation value is greater than the threshold value, the control unit 8 checks whether the number of times the variation evaluation value is determined to be greater than the threshold value (hereinafter, also referred to as "NG number of times") is equal to or less than a predetermined limit number of times (step S241). The limit number of times is an integer of 1 or more, and in the present embodiment, it is 2 times. The limit number of times may be changed variously.

[0083] When the NG number of times is equal to or less than the limit number of times, the imaging unit 51 waits without being driven until a predetermined waiting time stored in advance in the storage unit 801 elapses (step S242). The waiting time is measured from the end of imaging of a plurality of inspection images in step S21. The waiting time is preferably equal to or longer than the duration of the vibration of the stage 21 (hereinafter, also referred to as "vibration duration"), and more preferably longer than the vibration duration. On the other hand, from the viewpoint of shortening the time required for calibration, it is not preferable that the waiting time is excessively long. In the present embodiment, the waiting time is set to 0.5 seconds.

[0084] When the standby time elapses, the process returns to step S21, and the calibration pattern corresponding to the above-described one drawing head 41 is imaged a plurality of times again by the calibration camera 53, and a new plurality of inspection images are acquired (step S21). The new plurality (for example, five) of inspection images are sent to the control unit 8 and stored in the storage unit 801.

[0085] Subsequently, in the same manner as described above, the evaluation value acquisition unit 803 selects a new inspection image group that is a set of the above-described predetermined number (for example, five) of inspection images from the new plurality of inspection images. Then, the position detection unit 808 obtains the pattern position that is the position of the calibration pattern in each inspection image of the new inspection image group (step S22). Next, the evaluation value calculation unit 809 obtains a variation evaluation value, which is a parameter indicating the magnitude of the variation in the pattern positions of the predetermined number (for example, five) in the new inspection image group, from the above-described predetermined number (for example, five) of pattern positions obtained in step S22 (step S23).

[0086] Then, the correction image group setting unit 804 compares the variation evaluation value with the above-described threshold value (step S24). When the variation evaluation value is equal to or less than the threshold value, the inspection image group is set as the correction image group (step S25). When the variation evaluation value is greater than the threshold value, the number of NG times is confirmed (step S241). When the number of NG times is equal to or less than the limited number of times (for example, two or less), after the standby time (step S242) elapses, steps S21 to S24 are repeated in the same manner as described above.

[0087] On the other hand, when the number of NG times is greater than the limit number of times (for example, when it is 3 times or more), the calibration for one print head 41 during calibration is aborted (step S29). In other words, if an appropriate inspection image group cannot be obtained even when steps S21 to S24 are repeated one more time than the limit number of times (in this embodiment, 3 times) for one print head 41, the calibration for that one print head 41 is aborted. In this embodiment, the time required for steps S21 to S24 (that is, the time from the start of imaging of a plurality of inspection images to the end of comparison between the variation evaluation value and the threshold value) is several milliseconds to several tens of milliseconds, and the waiting time in step S242 is 0.5 seconds as described above. Therefore, the time required to repeat steps S21 to S24 three times for one print head 41 is about 1 second.

[0088] For the print head 41 for which calibration has been aborted, for example, calibration is performed again after the calibration of the other print heads 41 has been completed. The re - calibration for the print head 41 for which calibration has been aborted in step S29 is performed within the above - mentioned loading and unloading time, or after the completion of the loading and unloading process of the substrate 9 and before the start of printing on the substrate 9.

[0089] When the correction image group is set in step S25, correction information used for correcting the light irradiation position from the print head 41 is obtained by the correction information acquisition unit 805 (see FIG. 5) based on the pattern positions in the above - mentioned predetermined number (for example, 5) of inspection images included in the correction image group (step S26).

[0090] Specifically, the arithmetic mean of the pattern positions in the above-mentioned predetermined number (for example, five) of inspection images included in the correction image group is obtained, and the arithmetic mean is compared with the designed irradiation position (hereinafter also referred to as the "designed position") on the scale portion 52 of the calibration pattern irradiated from the drawing head 41. Then, the distances in the X direction and the Y direction (that is, the deviation amount from the designed position) between the arithmetic mean of the pattern positions and the designed position are obtained. The correction information acquisition unit 805 obtains the above-mentioned correction information for correcting the irradiation position of the light from the drawing head 41 to match the designed position based on the deviation amount. The correction information is, for example, information for correcting the drawing data of the pattern drawn on the substrate 9 according to the deviation amount. Alternatively, the correction information may be information for correcting the movement of the substrate 9 by the stage movement mechanism 22 when drawing the pattern on the substrate 9.

[0091] In the drawing apparatus 1, when the acquisition of the correction image group corresponding to one drawing head 41 (step S25) is completed, for example, in parallel with the acquisition of the correction information corresponding to the one drawing head 41 (step S26), the calibration camera 53 is moved in the X direction by the camera movement mechanism 54. Alternatively, the movement of the calibration camera 53 in the X direction may be performed after the acquisition of the correction information corresponding to the one drawing head 41 (step S26) is completed. The calibration camera 53 is arranged in a stationary state vertically below one other drawing head 41 adjacent to the one drawing head 41 for which the correction image group has been acquired in the X direction.

[0092] The time required for the movement of the calibration camera 53 between two adjacent drawing heads 41 in the X direction (for example, 0.8 seconds) is usually longer than the time required for the acquisition of the correction information in step S26 (for example, several milliseconds). Therefore, the acquisition of the correction information in step S26 ends before the calibration camera 53 is arranged vertically below the other one drawing head 41.

[0093] When the calibration camera 53 is disposed vertically below the other one of the drawing heads 41, steps S21 to S26 are performed on the other one of the drawing heads 41 in the same manner as described above to obtain correction information. In the drawing apparatus 1, steps S21 to 26 are sequentially performed on all the drawing heads 41 of the drawing unit 4, and the correction information corresponding to each drawing head 41 is sequentially obtained.

[0094] In the drawing apparatus 1, as described above, for one drawing head 41 in which the inspection image is captured during the vibration of the stage 21 that occurs when the substrate 9 is loaded, by repeating steps S21 to S24 (that is, acquisition of the inspection image group, etc.), the correction information is accurately obtained. Further, the duration of the vibration of the stage 21 that occurs when the substrate 9 is loaded is 0.5 seconds, and the movement time of the calibration camera 53 between adjacent drawing heads 41 is 0.8 seconds. Therefore, for the other drawing heads 41 except the one drawing head 41, the acquisition timing of the inspection image does not overlap with the above vibration of the stage 21. Therefore, for the other drawing heads 41, the correction information is accurately obtained without repeating steps S21 to S24.

[0095] In the present embodiment, as described above, the time required for steps S21 to S24 in each drawing head 41 is several milliseconds to several tens of milliseconds, and for one of the six drawing heads 41, the maximum time required when steps S21 to S24 are repeated with a waiting time in between is about 1 second. Further, the movement time of the calibration camera 53 between adjacent drawing heads 41 is 0.8 seconds. For this reason, the time required to obtain the correction information for all of the six drawing heads 41 is about 5 seconds, which is equal to or less than the above-described loading / unloading time of the substrate 9 (for example, about 6 seconds). Therefore, an increase in the tact time due to the calibration of the drawing heads 41 is prevented or suppressed.

[0096] In the drawing apparatus 1, when acquiring an inspection image of one drawing head 41, irradiation of a calibration pattern from other drawing heads 41 may be stopped, or a calibration pattern may be irradiated from other drawing heads 41 to the scale portion 52.

[0097] As described above, the loading and unloading of the substrate 9 with respect to the drawing apparatus 1 may be automatically performed by the loading apparatus 95, or may be manually performed by an operator. In other words, the loading of the substrate 9 with respect to the drawing apparatus 1 can be switched between automatic loading by the loading apparatus 95 and manual loading by the operator. The same applies to the unloading of the substrate 9 from the drawing apparatus 1. When the substrate 9 is manually loaded into the drawing apparatus 1, the duration of the vibration of the stage 21 when the substrate 9 is placed on the substrate holding portion 25 may be different from the vibration duration (0.5 seconds) when the substrate 9 is automatically loaded.

[0098] In the drawing apparatus 1, the standby time in step S242 can be switched between a first standby time corresponding to the automatic loading of the substrate 9 and a second standby time corresponding to the manual loading of the substrate 9. The second standby time is a time different from the first standby time and is stored in advance in the storage unit 801 in the same manner as the first standby time. When the vibration duration of the stage 21 during manual loading of the substrate 9 is longer than the vibration duration during automatic loading of the substrate 9, it is preferable that the second standby time be set longer than the first standby time (for example, 0.5 seconds). Also, when the vibration duration of the stage 21 during manual loading of the substrate 9 is shorter than the vibration duration during automatic loading of the substrate 9, it is preferable that the second standby time be set shorter than the first standby time. The switching between the first standby time and the second standby time is realized, for example, by an operator performing a predetermined input via the input unit 86 of the control unit 8.

[0099] In the drawing apparatus 1, when acquiring the inspection image of the drawing head 41, for example, if vibrations or the like of the stage 21 occur due to a cause other than the loading of the substrate 9 and the variation evaluation value becomes larger than the threshold value, similar to the case where the vibrations are caused by the loading of the substrate 9, by repeating steps S21 to S24, the correction information of the drawing head 41 can be accurately obtained. Further, for two or more drawing heads 41, if the variation evaluation value becomes larger than the threshold value, for each of the two or more drawing heads 41, by repeating steps S21 to S24, the correction information of the two or more drawing heads 41 can be accurately obtained.

[0100] In the drawing apparatus 1, if the correction image group of each drawing head 41 is set in step S11 described above, the acquisition of the correction information of each drawing head 41 (step S26) may be performed after the loading port 61 is closed and before the drawing on the substrate 9 is started. For example, the acquisition of the correction information of each drawing head 41 may be performed while the substrate 9 and the stage 21 are moving from the loading position shown in FIGS. 7A to 7D to the standby position shown in FIG. 7F, or while the substrate 9 and the stage 21 are waiting at the standby position until the drawing starts.

[0101] In the drawing apparatus 1, the acquisition of the correction information for each drawing head 41 (step S11) and the alignment process of the substrate 9 (step S12) only need to be completed before the start of the pattern drawing on the substrate 9. Further, the acquisition of the correction information for each drawing head 41 may be performed before or after the alignment process of the substrate 9, or may be performed substantially in parallel.

[0102] Next, a second calibration method will be described. When calibrating the drawing head 41 by the second calibration method, first, in the same manner as in step S21, with the scale portion 52 positioned at the calibration position, the calibration camera 53 is moved in the X direction and disposed directly below one of the drawing heads 41 to be calibrated. Then, with the calibration camera 53 stationary directly below the drawing head 41, a calibration pattern is irradiated from the drawing head 41 onto the scale portion 52.

[0103] Subsequently, the calibration camera 53 captures the calibration pattern over a predetermined imaging time, and a plurality of inspection images are acquired (step S31). The imaging time of the calibration pattern in step S31 is longer than, for example, the vibration duration of the stage 21 (e.g., 0.5 seconds) when the substrate 9 is loaded as described above. In the present embodiment, the imaging time of the calibration pattern is 1 second, and a large number of inspection images are acquired during the 1 second. Note that the number of inspection images acquired in step S31 may be determined variously as long as it is larger than the number of inspection images included in the inspection image group selected in step S32 described later.

[0104] Next, an evaluation value acquisition unit 803 (see FIG. 5) selects an inspection image group, which is a set of a predetermined number of two or more inspection images, from the plurality of inspection images described above. In the present embodiment, among the large number of inspection images acquired in step S31, the first acquired inspection image and the four inspection images acquired subsequently to the inspection image are selected as the inspection image group. In other words, among the imaging times of the calibration patterns in step S31, five consecutive inspection images acquired between several milliseconds and several tens of milliseconds from the start of acquisition of the first inspection image are selected as the inspection image group. Then, in substantially the same manner as in step S22, a pattern position, which is the position of the calibration pattern in each inspection image of the inspection image group, is obtained by the position detection unit 808 (step S32). The predetermined number of pattern positions (five pattern positions in the present embodiment) corresponding to the predetermined number of inspection images described above are sent from the position detection unit 808 to the evaluation value calculation unit 809.

[0105] Note that the predetermined number of inspection images selected as the inspection image group in step S32 do not necessarily have to be inspection images captured in the vicinity of the start of step S31 and may be changed in various ways. For example, among the large number of inspection images acquired in step S31, the last acquired inspection image and the four inspection images continuously acquired prior to the inspection image may be selected as the inspection image group. In other words, the predetermined number of inspection images selected as the inspection image group may be inspection images captured in the vicinity of the end of step S31. Alternatively, five consecutive inspection images acquired near the center of the imaging time of the calibration pattern in step S31 may be selected as the inspection image group.

[0106] When step S32 ends, in substantially the same manner as in step S23, a variation evaluation value is obtained by the evaluation value calculation unit 809 from the predetermined number of pattern positions obtained by the position detection unit 808 (step S33). The variation evaluation value obtained by the evaluation value calculation unit 809 is sent to the correction image group setting unit 804.

[0107] In the correction image group setting unit 804, in substantially the same manner as step S24, the variation evaluation value is compared with the above-described threshold value (step S34). Then, when the variation evaluation value is less than or equal to the threshold value, in substantially the same manner as step S25, the inspection image group is set as a correction image group suitable for calibration of the drawing head 41 (step S35).

[0108] On the other hand, when the variation evaluation value is greater than the threshold value, it is determined that the inspection image group is inappropriate as a correction image group. As described above, typically, when the imaging timing of one or more inspection images included in the inspection image group overlaps with the vibration duration of the stage 21 at the time of loading the substrate 9, the variation evaluation value is likely to be greater than the threshold value.

[0109] When the variation evaluation value is greater than the threshold value in step S34, the process returns to step S32, and a new inspection image group is selected from the plurality of inspection images acquired in step S31. The new inspection image group is a set of the predetermined number of inspection images different from the predetermined number of inspection images included in the inspection image group determined to be inappropriate in step S34. From the viewpoint of avoiding the above-described vibration duration of the stage 21, it is preferable that the imaging timing of the inspection images included in the new inspection image group is as far as possible from the imaging timing of the inspection images included in the inspection image group determined to be inappropriate as a correction image group. The new inspection image group is, for example, five inspection images imaged near the end of step S31.

[0110] In the position detection unit 808, the pattern position in each inspection image of the new inspection image group is obtained (step S32). Then, a new variation evaluation value is obtained from the predetermined number of pattern positions in the new inspection image group by the evaluation value calculation unit 809 (step S33).

[0111] Then, the correction image group setting unit 804 compares the new variation evaluation value with the threshold value (step S34). When the new variation evaluation value is equal to or less than the threshold value, the inspection image group is set as the correction image group (step S35). When the variation evaluation value is greater than the threshold value, the process returns to step S32 as described above, and the inspection image group is changed until the correction image group is set, and steps S32 to S34 are repeated.

[0112] When the correction image group is set in step S35, in substantially the same manner as in step S26, correction information used for correcting the irradiation position of light from the drawing head 41 is obtained by the correction information acquisition unit 805 based on the pattern positions in the above-mentioned predetermined number (for example, five) of inspection images included in the correction image group (step S36).

[0113] In the drawing apparatus 1, when the acquisition of the correction image group corresponding to one drawing head 41 (step S35) is completed, for example, in parallel with the acquisition of the correction information corresponding to the one drawing head 41 (step S36), the calibration camera 53 is moved in the X direction by the camera moving mechanism 54. Alternatively, the movement of the calibration camera 53 in the X direction may be performed after the acquisition of the correction information corresponding to the one drawing head 41 (step S36) is completed. The calibration camera 53 is arranged in a stationary state vertically below one drawing head 41 and another drawing head 41 adjacent to the one drawing head 41 in the X direction for which the correction image group has been acquired.

[0114] The time required for the movement of the calibration camera 53 between two adjacent drawing heads 41 in the X direction (for example, 0.8 seconds) is usually longer than the time required for the acquisition of the correction information in step S36 (for example, several milliseconds). Therefore, the acquisition of the correction information in step S36 ends before the calibration camera 53 is arranged vertically below the other drawing head 41.

[0115] When the calibration camera 53 is disposed vertically below the other one of the drawing heads 41, steps S31 to S36 are performed for the other one of the drawing heads 41 in the same manner as described above, and correction information is acquired. In the drawing apparatus 1, steps S31 to S36 are sequentially performed for all the drawing heads 41 of the drawing unit 4, and the correction information corresponding to each drawing head 41 is sequentially acquired.

[0116] In the drawing apparatus 1, as described above, for one drawing head 41 in which an inspection image is captured during the vibration of the stage 21 that occurs when the substrate 9 is loaded, steps S32 to S34 (that is, selection of an inspection image group, etc.) are repeated, so that correction information is accurately obtained. As described above, the vibration duration of the stage 21 when the substrate 9 is loaded is 0.5 seconds, and the imaging time of the calibration pattern for one drawing head 41 is longer than the vibration duration. For this reason, an appropriate inspection image group that is not affected by the vibration of the stage 21 can be selected from the plurality of inspection images captured in step S31 for the one drawing head 41. Further, for the other drawing heads 41 other than the one drawing head 41, the acquisition timing of the inspection images does not overlap with the vibration of the stage 21. Therefore, for the other drawing heads 41, correction information is accurately obtained without repeating steps S32 to S34.

[0117] As described above, in the drawing apparatus 1, the moving time of the calibration camera 53 between adjacent drawing heads 41 is 0.8 seconds. Also, the imaging time of the calibration pattern for each drawing head 41 in the second calibration method is 1 second. Therefore, the time required to acquire the correction information for all six drawing heads 41 is shorter than the loading and unloading time of the substrate 9 (for example, about 15 seconds) during the manual loading described above.

[0118] In addition, for one drawing head 41, if the correction image group cannot be set even when steps S32 to S34 are repeated a predetermined number of times, the calibration for the one drawing head 41 may be aborted. In this case, for example, after the calibration of other drawing heads 41 is completed, the calibration is performed again for the one drawing head 41 for which the calibration has been aborted. The re-calibration for the one drawing head 41 for which the calibration has been aborted is performed within the above-described loading and unloading time, or after the completion of the loading and unloading process of the substrate 9 and before the start of drawing on the substrate 9.

[0119] As described above, the drawing apparatus 1 that irradiates light on the substrate 9 to draw a pattern includes a stage 21, a drawing head 41, a main scanning mechanism (i.e., the first moving mechanism 23), a scale portion 52, a calibration camera 53, a correction image group setting unit 804, a correction information acquisition unit 805, and a drawing control unit 807. The stage 21 is provided with a substrate holding unit 25 that holds the substrate 9. The drawing head 41 irradiates the substrate 9 with modulated light. The first moving mechanism 23 relatively moves the stage 21 with respect to the drawing head 41 in the main scanning direction (in the above example, the Y direction) parallel to the upper surface 91 of the substrate 9. The scale portion 52 is provided on the stage 21. The scale portion 52 is located at the calibration position below the drawing head 41 in a state where the stage 21 is located at the loading position where the substrate 9 is loaded and unloaded with respect to the substrate holding unit 25. The calibration camera 53 images the calibration pattern irradiated from the drawing head 41 to the scale portion 52 in a state where the scale portion 52 is located at the calibration position, and acquires a plurality of inspection images each including the scale portion 52 and the calibration pattern.

[0120] The evaluation value acquisition unit 803 obtains a variation evaluation value by obtaining the pattern position, which is the position of the calibration pattern in each inspection image, for an inspection image group that is a set of two or more predetermined numbers (for example, five) of inspection images included in the plurality of inspection images acquired by the calibration camera 53. The variation evaluation value indicates the magnitude of the variation in the pattern positions of the predetermined number in the inspection image group. The correction image group setting unit 804 sets the inspection image group as a correction image group when the variation evaluation value is equal to or less than a predetermined threshold value. The correction information acquisition unit 805 acquires correction information used for correcting the irradiation position of light from the drawing head 41 based on the pattern positions of the predetermined number in the correction image group. The drawing control unit 807 controls the drawing head 41 and the first moving mechanism 23 based on the drawing data and the correction information, thereby relatively moving the substrate 9 in the main scanning direction with respect to the drawing head 41 and causing the drawing head 41 to perform drawing on the substrate.

[0121] Thereby, it is possible to prevent an inspection image group having variations in pattern positions due to disturbances or the like (for example, vibrations of the stage 21) from being set as the correction image group. Therefore, it is possible to accurately acquire correction information while excluding the influence of disturbances or the like. Further, calibration of the drawing head 41 can be performed in parallel with the loading and unloading of the substrate 9. As a result, it is possible to accurately perform calibration of the drawing head 41 while suppressing an increase in the tact time. Note that in the drawing apparatus 1, even if the variation in the pattern positions in the inspection image group is due to factors other than the vibrations of the stage 21, calibration of the drawing head 41 can be accurately performed while suppressing an increase in the tact time in the same manner as described above.

[0122] As described above, in the first calibration method, when the variation evaluation value is greater than the threshold value, the calibration camera 53 acquires a new plurality of inspection images after a predetermined waiting time has elapsed since the imaging of the plurality of inspection images was completed. Further, the evaluation value acquisition unit 803 obtains a new variation evaluation value for a new inspection image group that is a set of a predetermined number (five in the above example) of inspection images included in the new plurality of inspection images. Then, when the new variation evaluation value is less than or equal to the threshold value, the correction image group setting unit 804 sets the new inspection image group as the correction image group. In this way, when the variation in the pattern positions in the inspection image group is large, by re-acquiring the inspection image group after the waiting time has elapsed and setting the correction image group, it is possible to suitably acquire highly accurate correction information.

[0123] As described above, in the first calibration method, the variation in the pattern positions of a predetermined number in the inspection image group is caused by, for example, the vibration of the stage 21 when the substrate 9 is loaded into the substrate holding unit 25. In this case, it is preferable that the waiting time is equal to or longer than the duration of the vibration of the stage 21 (0.5 seconds in the above example) when the substrate 9 is loaded into the substrate holding unit 25. Thereby, the re-acquisition of the inspection image group can be suitably performed after the vibration of the stage 21 has stopped. As a result, more accurate correction information can be obtained.

[0124] As described above, in the first calibration method, when the substrate 9 is loaded into the substrate holding unit 25, for example, either automatic loading by the loading device 95 or manual loading by an operator is performed. In this case, it is preferable that the waiting time is switchable between a first waiting time corresponding to automatic loading and a second waiting time corresponding to manual loading and different from the first waiting time. Thereby, without making the waiting time excessively long, the waiting time can be determined according to the vibration duration of the stage 21 during automatic loading and the vibration duration of the stage 21 during manual loading, respectively, and the re-acquisition of the inspection image group can be suitably performed. As a result, while suitably suppressing an increase in the tact time, highly accurate correction information can be suitably obtained.

[0125] As described above, in the second calibration method, the number of a plurality of inspection images acquired by the calibration camera 53 is larger than the number of inspection images included in the inspection image group. And when the variation evaluation value is larger than the threshold value, the evaluation value acquisition unit 803 selects, from the plurality of inspection images, a new inspection image group which is a set of the above-mentioned predetermined number of inspection images different from the inspection image group, and obtains a new variation evaluation value for the new inspection image group. Further, when the new variation evaluation value is equal to or less than the threshold value, the correction image group setting unit 804 sets the new inspection image group as the correction image group. Thus, when the variation in the pattern positions in the inspection image group is large, by selecting another inspection image group from the plurality of acquired inspection images and setting the correction image group, highly accurate correction information can be suitably acquired.

[0126] As described above, in the second calibration method, the variation in the predetermined number of pattern positions in the inspection image group is caused by, for example, the vibration of the stage 21 when the substrate 9 is carried into the substrate holding unit 25. In this case, it is preferable that the time required for acquiring the plurality of inspection images by the calibration camera 53 is longer than the duration of the vibration of the stage 21 when the substrate 9 is carried into the substrate holding unit 25. Thereby, the acquired plurality of inspection images surely include inspection images not affected by the vibration of the stage 21. And by selecting the inspection image as the inspection image group, more accurate correction information can be acquired.

[0127] As described above, in the drawing apparatus 1 illustrated in FIG. 1, a plurality of drawing heads 41 including the above-described drawing head 41 and each irradiating the substrate 9 with modulated light are arranged in an arrangement direction (in the above example, the X direction) that is parallel to the upper surface of the substrate 9 and inclined with respect to the main scanning direction above the scale portion 52. The calibration camera 53 preferably moves in the arrangement direction in a state where the scale portion 52 is located at the calibration position, and sequentially captures a plurality of calibration patterns respectively irradiated from the plurality of drawing heads 41 to the scale portion 52, thereby obtaining a plurality of inspection images corresponding to each of the plurality of drawing heads 41. Thereby, compared with the case where a plurality of calibration cameras are provided in the calibration unit 5, the structure of the drawing apparatus 1 can be simplified, and the manufacturing cost of the drawing apparatus 1 can be reduced.

[0128] In this case, it is preferable that the evaluation value acquisition unit 803 obtains a variation evaluation value for each of the plurality of drawing heads 41, and the correction image group setting unit 804 sets a correction image group for each of the plurality of drawing heads 41. Further, the correction information acquisition unit 805 preferably acquires correction information for each of the plurality of drawing heads 41, and the drawing control unit 807 controls the plurality of drawing heads 41 and the main scanning mechanism (that is, the first movement mechanism 23) based on the drawing data and the correction information for each of the plurality of drawing heads 41, thereby causing the drawing on the substrate 9 to be executed. Thereby, for each of the plurality of drawing heads 41, it is possible to accurately acquire correction information while eliminating the influence of disturbances and the like. As a result, it is possible to accurately calibrate the plurality of drawing heads 41 while suppressing an increase in the tact time.

[0129] As described above, the time required from the acquisition of a plurality of inspection images corresponding to each of the plurality of drawing heads 41 by the calibration camera 53 to the setting of the correction image group for each of the plurality of drawing heads 41 (steps S21 to S25, steps S31 to 35) is preferably equal to or less than the time required to carry out one substrate 9 from the substrate holding unit 25 and carry a new substrate 9 into the substrate holding unit 25 (i.e., the loading / unloading time). Thereby, after the loading / unloading of the substrate 9 is completed, the movement of the stage 21 can be started immediately. Therefore, an increase in the tact time due to calibration can be prevented.

[0130] As described above, the acquisition of a plurality of inspection images corresponding to each of the plurality of drawing heads 41 by the calibration camera 53 is preferably performed every time a substrate 9 is carried into the substrate holding unit 25. Thereby, high-precision drawing can be realized while suppressing an increase in the tact time.

[0131] In the above-described drawing method, in a state where the stage 21 provided with the substrate holding portion 25 and the scale portion 52 is located at the loading position where the loading and unloading of the substrate 9 with respect to the substrate holding portion 25 are performed, the calibration pattern irradiated from the drawing head 41 is imaged on the scale portion 52 located at the calibration position below the drawing head 41, and a plurality of inspection images each including the scale portion 52 and the calibration pattern are acquired (steps S21, S31); for an inspection image group that is a set of two or more predetermined numbers of inspection images included in the plurality of inspection images acquired in steps S21, S31, the pattern position that is the position of the calibration pattern in each inspection image is obtained, and a variation evaluation value indicating the magnitude of the variation of the predetermined number of pattern positions in the inspection image group is obtained (steps S22 to S23, S32 to S33); when the variation evaluation value is equal to or less than a predetermined threshold value, a step of setting the inspection image group as a correction target image group (steps S24 to S25, S34 to S35); based on the predetermined number of pattern positions of the correction target image group, a step of acquiring correction information used for correcting the irradiation position of the light from the drawing head 41 (steps S26, S36); and a step of irradiating the substrate 9 that relatively moves in the main scanning direction with respect to the drawing head 41 with the light modulated from the drawing head 41 based on the drawing data and the correction information to perform drawing on the substrate 9 (step S13). Thereby, as described above, it is possible to accurately calibrate the drawing head 41 while suppressing an increase in tact time.

[0132] In the above-described drawing apparatus 1 and drawing method, various modifications are possible.

[0133] For example, in the drawing apparatus 1, it is not necessarily required that both automatic loading of the substrate 9 by the loading apparatus 95 and manual loading of the substrate 9 by an operator are possible, and only one of them may be possible. Further, the structure of the loading apparatus 95 is not limited to the above-described one and may be variously modified.

[0134] The above variation evaluation value is not necessarily limited to the standard deviation or variance of the pattern positions of the above predetermined number. For example, it may be variously changed such as the sum of the absolute values of the deviations of the pattern positions of the predetermined number, the arithmetic mean of the absolute values of the deviations, the sum of the squares of the deviations, and the like.

[0135] In the drawing apparatus 1, the time required from the acquisition of a plurality of inspection images corresponding to each of the plurality of drawing heads 41 by the calibration camera 53 to the setting of the correction image group for each of the plurality of drawing heads 41 (steps S21 to S25, steps S31 to 35) may be longer than the time required to carry out one substrate 9 from the substrate holding unit 25 and carry a new substrate 9 into the substrate holding unit 25 (that is, the carry-in / out time), or may be substantially the same. In any case, by performing the carry-in / out of the substrate 9 and the calibration of the drawing head 41 in parallel, the tact time can be shortened.

[0136] In the first calibration method, the standby time may be shorter than the duration of the vibration of the stage 21 when the substrate 9 is carried into the substrate holding unit 25, or may be substantially the same.

[0137] In the second calibration method, the time required for the acquisition of a plurality of inspection images by the calibration camera 53 may be shorter than the duration of the vibration of the stage 21 when the substrate 9 is carried into the substrate holding unit 25, or may be substantially the same.

[0138] In the above example, the imaging of the calibration pattern by the calibration camera 53 (that is, the acquisition of the inspection image) is performed in a state where the calibration camera 53 is stationary substantially vertically below each drawing head 41, but it is not limited thereto. For example, the calibration camera 53 may sequentially image the calibration patterns corresponding to each drawing head 41 while moving in the X direction below the plurality of drawing heads 41. In this case, a plurality of calibration patterns may be sequentially imaged as a moving image, and a plurality of inspection images (still images) corresponding to each drawing head 41 may be extracted from the moving image.

[0139] In the drawing device 1, in the imaging unit 51 of the calibration unit 5, a plurality (i.e., the same number as the drawing heads 41) of calibration cameras 53 corresponding to the plurality of drawing heads 41 are arranged in the X direction directly below the scale unit 52, and inspection images of the plurality of drawing heads 41 may be acquired substantially simultaneously.

[0140] In the drawing device 1, the scale unit 52 does not necessarily have to be translucent, and the calibration camera 53 does not necessarily have to be attached to the stage 21. For example, the scale unit 52 may be a reflector that reflects the light irradiated from the drawing head 41 in a predetermined direction. The calibration camera 53 may be fixed to the frame of the drawing device 1 or the like at a position separated from the stage 21, and may capture an inspection image including the calibration pattern irradiated on the scale unit 52 and the scale on the scale unit 52 by receiving the reflected light from the scale unit 52.

[0141] In the light source unit 42 of the drawing head 41, light may be emitted from two or more light sources even during the imaging of the inspection image. Also, the light source unit 42 does not necessarily have to include a plurality of light sources, and may include only one light source.

[0142] The stage 21 may be relatively moved in the main scanning direction with respect to the drawing head 41 by the first moving mechanism 23. Therefore, for example, the stage 21 may be fixed, and above the stage 21, the drawing head 41 may be moved in the main scanning direction by the first moving mechanism 23. Similarly, the drawing head 41 may be moved in the sub-scanning direction by the second moving mechanism 24.

[0143] In the drawing device 1, calibration does not necessarily have to be performed every time the substrate 9 is carried in. For example, calibration of the drawing head 41 may be performed every time the drawing of patterns for two or more predetermined numbers of substrates 9 is completed.

[0144] The above-described substrate 9 is not necessarily limited to a printed circuit board. In the drawing apparatus 1, for example, pattern drawing may be performed on a semiconductor substrate, a substrate for a semiconductor package, a glass substrate for a flat panel display device such as a liquid crystal display device or a plasma display device, a glass substrate for a photomask, a substrate for a solar cell panel, or the like.

[0145] The configurations in the above-described embodiments and each modification example may be appropriately combined as long as they do not conflict with each other.

Explanation of Reference Numerals

[0146] 1 Drawing apparatus 9 Substrate 21 Stage 23 First moving mechanism 25 Substrate holding portion 41 Drawing head 52 Scale portion 53 Calibration camera 91 (Upper surface of the) substrate 95 Loading apparatus 803 Evaluation value acquisition unit 804 Correction image group setting unit 805 Correction information acquisition unit 807 Drawing control unit S11~S14,S21~S26,S29,S31~S36,S241~S242 Steps

Claims

1. A drawing apparatus for performing pattern drawing by irradiating a substrate with light, comprising: a stage provided with a substrate holding unit for holding the substrate; a drawing head for irradiating the substrate with modulated light; a main scanning mechanism for relatively moving the stage with respect to the drawing head in a main scanning direction parallel to the upper surface of the substrate; a scale portion located at a calibration position below the drawing head in a state where the stage is located at a loading position provided on the stage and where loading and unloading of the substrate to and from the substrate holding unit are performed; a calibration camera for imaging a calibration pattern irradiated from the drawing head onto the scale portion in a state where the scale portion is located at the calibration position, and acquiring a plurality of inspection images each including the scale portion and the calibration pattern; an evaluation value acquisition unit for obtaining a pattern position which is the position of the calibration pattern in each inspection image for an inspection image group which is a set of two or more predetermined numbers of inspection images included in the plurality of inspection images acquired by the calibration camera, and obtaining a variation evaluation value indicating the magnitude of variation of the predetermined number of the pattern positions in the inspection image group; a correction image group setting unit for setting the inspection image group as a correction image group when the variation evaluation value is equal to or less than a predetermined threshold; a correction information acquisition unit for acquiring correction information used for correcting the irradiation position of light from the drawing head based on the predetermined number of the pattern positions of the correction image group; a drawing control unit for controlling the drawing head and the main scanning mechanism based on drawing data and the correction information, and causing the drawing head to perform drawing on the substrate while relatively moving the substrate with respect to the drawing head in the main scanning direction; A drawing apparatus comprising the above components.

2. The drawing apparatus according to Claim 1, wherein when the variation evaluation value is greater than the threshold, the calibration camera acquires a new plurality of inspection images after elapse of a predetermined waiting time from the end of imaging of the plurality of inspection images, the evaluation value acquisition unit obtains a new variation evaluation value for a new inspection image group which is a set of the predetermined number of inspection images included in the new plurality of inspection images, and the correction image group setting unit sets the new inspection image group as the correction image group when the new variation evaluation value is equal to or less than the threshold.

3. The drawing apparatus according to claim 2, wherein the variation in the pattern positions of the predetermined number in the inspection image group is caused by the vibration of the stage that occurs when the substrate is loaded into the substrate holding unit, and the standby time is equal to or longer than the duration of the vibration of the stage when the substrate is loaded into the substrate holding unit.

4. The drawing apparatus according to claim 3, wherein when the substrate is loaded into the substrate holding unit, either automatic loading by a loading device or manual loading by an operator is performed, and the standby time is switchable between a first standby time corresponding to the automatic loading and a second standby time corresponding to the manual loading and different from the first standby time.

5. The drawing apparatus according to claim 1, wherein the number of the plurality of inspection images acquired by the calibration camera is larger than the number of inspection images included in the inspection image group, when the variation evaluation value is larger than the threshold value, the evaluation value acquisition unit selects a new inspection image group that is a set of the predetermined number of inspection images different from the inspection image group from the plurality of inspection images, obtains a new variation evaluation value for the new inspection image group, and the correction image group setting unit sets the new inspection image group as the correction image group when the new variation evaluation value is equal to or less than the threshold value.

6. The drawing apparatus according to claim 5, wherein the variation in the pattern positions of the predetermined number in the inspection image group is caused by the vibration of the stage that occurs when the substrate is loaded into the substrate holding unit, and the time required to acquire the plurality of inspection images by the calibration camera is longer than the duration of the vibration of the stage when the substrate is loaded into the substrate holding unit.

7. The drawing apparatus according to any one of claims 1 to 6, including the drawing head, and a plurality of drawing heads each irradiating the substrate with modulated light are arranged in an array direction parallel to the upper surface of the substrate and inclined with respect to the main scanning direction above the scale portion, wherein the calibration camera moves in the array direction in a state where the scale portion is located at the calibration position, and sequentially captures a plurality of calibration patterns respectively irradiated from the plurality of drawing heads to the scale portion, thereby acquiring the plurality of inspection images corresponding to the plurality of drawing heads respectively. The evaluation value acquisition unit obtains the variation evaluation value for each of the plurality of drawing heads. The correction image group setting unit sets the correction image group for each of the plurality of drawing heads. The correction information acquisition unit acquires the correction information for each of the plurality of drawing heads. The drawing control unit controls the plurality of drawing heads and the main scanning mechanism based on the drawing data and the correction information for each of the plurality of drawing heads, thereby causing the drawing device to perform drawing on the substrate.

8. The drawing device according to claim 7, The time required from the acquisition of the plurality of inspection images corresponding to each of the plurality of drawing heads by the calibration camera to the setting of the correction image group for each of the plurality of drawing heads is equal to or less than the time required to carry out one substrate from the substrate holding unit and carry a new substrate into the substrate holding unit.

9. The drawing device according to claim 7, The acquisition of the plurality of inspection images corresponding to each of the plurality of drawing heads by the calibration camera is performed each time a substrate is carried into the substrate holding unit.

10. A drawing method for performing pattern drawing by irradiating a substrate with light, a) In a state where a stage provided with a substrate holding unit and a scale unit is located at a loading position where loading and unloading of the substrate to and from the substrate holding unit are performed, imaging the calibration pattern irradiated from the drawing head on the scale unit located at the calibration position below the drawing head, and obtaining a plurality of inspection images each including the scale unit and the calibration pattern; b) For an inspection image group that is a set of two or more predetermined numbers of inspection images included in the plurality of inspection images obtained in step a), obtaining the pattern position that is the position of the calibration pattern in each inspection image, and obtaining a variation evaluation value indicating the magnitude of the variation of the predetermined number of the pattern positions in the inspection image group; c) When the variation evaluation value is equal to or less than a predetermined threshold value, setting the inspection image group as a correction image group; d) Obtaining correction information used for correcting the irradiation position of light from the drawing head based on the predetermined number of the pattern positions of the correction image group. e) A step of performing drawing on the substrate by irradiating the substrate that relatively moves in the main scanning direction with respect to the drawing head with the light modulated from the drawing head based on the drawing data and the correction information; A drawing method comprising the above.

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