Method for obtaining drawing position information and drawing method

Abstract

To provide a drawing position information acquisition method capable of improving relative position accuracy of a pattern drawn on both principal surfaces of a substrate.SOLUTION: A drawing position information acquisition method comprises: a step (step S33) for imaging a first principal surface of a correction substrate, and acquiring positions of two first reference marks; a step (step S34) for drawing a plurality of alignment marks on a second principal surface of the correction substrate; a step (step S36) for imaging the second principal surface of the correction substrate, and acquiring positions of two second reference marks and positions of the plurality of alignment marks; and a step (step S37) for acquiring drawing position information related to drawing positions of the plurality of alignment marks by an alignment mark drawing part, on the basis of the positions of the two first reference marks, and the positions of the two second reference marks and positions of the plurality of alignment marks. Therefore, it is possible to improve relative position accuracy of a pattern to be drawn on both principal surfaces of the substrate on a drawing device.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a drawing position information acquisition method for acquiring information regarding a drawing position in a drawing device, and a drawing method for drawing a pattern on a substrate using the information.

Background Art

[0002] Conventionally, pattern drawing has been performed by irradiating light onto a photosensitive material formed on a semiconductor substrate, a printed circuit board, or a glass substrate for an organic EL display device or a liquid crystal display device (hereinafter referred to as a "substrate").

[0003] For example, in the drawing device of Patent Document 1, pattern drawing is performed on both sides of a substrate. In this drawing device, in order to align the pattern drawing positions on both sides of the substrate, when drawing a pattern on the upper surface of the substrate held on a stage, light is irradiated from a light source built into the stage onto the back surface of the substrate to draw an alignment mark. Then, when the substrate is inverted and a pattern is drawn on the back surface of the substrate, alignment processing is performed using the alignment mark, thereby aligning the pattern drawing positions on both sides of the substrate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in the drawing apparatus described above, the position of the alignment marks drawn on the back of the substrate may deviate from the design position due to mounting errors of the light source built into the stage, etc. Therefore, it is conceivable to measure the deviation between the drawing position of the alignment marks and the design position in advance and correct this deviation when drawing the pattern after the substrate is inverted. As a method for measuring this deviation, it is conceivable to capture the light emitted from the light source built into the stage with a camera while the substrate is not placed on the stage, and determine the above deviation based on the position of the light in the captured image. However, with this method, the measurement accuracy of the deviation may not be high due to various factors such as the relationship between the wavelength of the light and the performance of the camera. For this reason, there is a limit to improving the relative positional accuracy of the patterns drawn on the main surfaces on both sides of the substrate.

[0006] This invention has been made in view of the above problems, and aims to improve the relative positional accuracy of patterns drawn on the main surfaces on both sides of a substrate. [Means for solving the problem]

[0007] One aspect of the present invention is a method for acquiring drawing position information in a drawing apparatus. The drawing apparatus comprises a stage for holding a substrate, a stage moving mechanism for moving the stage horizontally, an imaging unit for imaging the upper surface of the substrate held on the stage, a pattern drawing unit for drawing a pattern by irradiating light onto the upper surface of the substrate held on the stage, and an alignment mark drawing unit fixed to the stage and for irradiating light onto the lower surface of the substrate held on the stage, and for drawing a plurality of alignment marks that serve as a reference for the drawing position when drawing a pattern on the lower surface. The drawing position information acquisition method includes the steps of: a) preparing a correction substrate having two first reference marks on a first main surface and two second reference marks on a second main surface whose positions in a plan view coincide with the two first reference marks; b) arranging the correction substrate with the first main surface facing upward so as to cover the alignment mark drawing section and holding it with the stage; c) imaging the first main surface of the correction substrate with the imaging section to acquire the positions of the two first reference marks; d) drawing the plurality of alignment marks on the second main surface of the correction substrate with the alignment mark drawing section; and e) The process includes, after step d), holding the correction substrate with the second main surface facing upward using the stage; f) imaging the second main surface of the correction substrate with the imaging unit to obtain the positions of the two second reference marks and the positions of the plurality of alignment marks; and g) obtaining drawing position information regarding the drawing positions of the plurality of alignment marks by the alignment mark drawing unit based on the positions of the two first reference marks obtained in step c), and the positions of the two second reference marks and the plurality of alignment marks obtained in step f).

[0008] Aspect 2 of the present invention is a method for acquiring drawing position information according to aspect 1, wherein the drawing position information acquired in step g) is correction information indicating the discrepancy between the design position of the plurality of alignment marks and the drawing position of the plurality of alignment marks by the alignment mark drawing unit.

[0009] A third aspect of the present invention is a method for acquiring drawing position information according to aspect 1 (or aspect 1 or 2), wherein the two first reference marks are each openings on the first main surface of two through holes provided in the correction substrate, and the two second reference marks are each openings on the second main surface of the two through holes.

[0010] Aspect 4 of the present invention is a method for acquiring drawing position information according to Aspect 1 (which may be any one of Aspects 1 to 3), wherein the plurality of alignment marks are arranged along a predetermined alignment direction. The distance between the two first reference marks in the alignment direction is greater than or equal to the distance between the two alignment marks located at both ends of the alignment direction among the plurality of alignment marks.

[0011] Aspect 5 of the present invention is a method for acquiring drawing position information according to aspect 1 (which may be any one of aspects 1 to 4), wherein the drawing apparatus further comprises: another stage for holding a substrate; another stage moving mechanism for horizontally moving the other stage; and another alignment mark drawing unit fixed to the other stage and irradiating light onto the lower surface of the substrate held by the other stage, and drawing a plurality of other alignment marks that serve as a reference for the drawing position when drawing a pattern on the lower surface. The pattern drawing unit comprises: a drawing head for irradiating light downwards; and a drawing head moving mechanism for moving the drawing head between a first drawing position above the stage moving mechanism and a second drawing position above the other stage moving mechanism. The imaging unit comprises: an alignment camera; and a camera moving mechanism for moving the alignment camera between a first imaging position above the stage moving mechanism and a second imaging position above the other stage moving mechanism. The drawing position information acquisition method includes the steps of: h) positioning the correction substrate with the second main surface facing upward so as to cover the other alignment mark drawing section and holding it with the other stage; i) imaging the second main surface of the correction substrate with the imaging section to acquire the positions of the two second reference marks; j) drawing the other plurality of alignment marks on the first main surface of the correction substrate with the other alignment mark drawing section; and k) after step j) positioning the correction substrate with the first main surface facing upward with the other stage The process further comprises: l) holding by a camera; l) imaging the first main surface of the correction substrate with the imaging unit to obtain the positions of the two first reference marks and the positions of the other plurality of alignment marks; and m) obtaining another drawing position information relating to the drawing position of the other plurality of alignment marks by the other alignment mark drawing unit, based on the positions of the two second reference marks obtained in step i), and the positions of the two first reference marks and the other plurality of alignment marks obtained in step l).

[0012] Aspect 6 of the present invention is a method for acquiring drawing position information according to aspect 5, wherein the appearance of the plurality of alignment marks is the same as that of the others. The appearance of the other plurality of alignment marks is the same as that of the previous plurality of alignment marks, and is different from that of the previous plurality of alignment marks.

[0013] Aspect 7 of the present invention is a drawing method for drawing a pattern on a substrate, comprising: n) holding the substrate with one main surface facing upward using the stage; o) capturing positioning marks on the one main surface using the imaging unit, performing alignment processing of the substrate based on the output from the imaging unit, and drawing a pattern on the one main surface using the pattern drawing unit; p) drawing the plurality of alignment marks on the other main surface of the substrate using the alignment mark drawing unit; q) holding the substrate with the other main surface facing upward using the stage; and r) capturing the plurality of alignment marks on the other main surface using the imaging unit, performing alignment processing of the substrate based on the output from the imaging unit and the drawing position information acquired by any one of the drawing position information acquisition methods of aspects 1 to 6, and drawing a pattern on the other main surface using the pattern drawing unit with reference to the plurality of alignment marks. [Effects of the Invention]

[0014] This invention makes it possible to improve the relative positional accuracy of patterns drawn on the main surfaces on both sides of the substrate. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view showing a drawing device. [Figure 2] This is a plan view showing a magnified portion of the stage. [Figure 3] This is a longitudinal cross-section showing the marker. [Figure 4] This is a bottom view showing the alignment marks. [Figure 5] This diagram shows the process of drawing patterns onto a circuit board. [Figure 6] It is a diagram showing the flow of pattern drawing on a substrate. [Figure 7] It is a plan view showing a correction substrate. [Figure 8] It is a bottom view showing a correction substrate. [Figure 9] It is a diagram showing the flow of acquisition of drawing position information. [Figure 10] It is a plan view showing a correction substrate and a stage. [Figure 11] It is a plan view showing a correction substrate and a stage. [Figure 12] It is a perspective view showing a drawing device. [Figure 13] It is a plan view showing an enlarged part of a stage. [Figure 14] It is a bottom view showing an alignment mark. [Figure 15] It is a diagram showing the flow of acquisition of drawing position information. [Figure 16] It is a plan view showing a correction substrate and a stage. [Figure 17] It is a plan view showing a correction substrate and a stage.

Embodiments for Carrying Out the Invention

[0016] FIG. 1 is a perspective view showing a drawing device 1 in which information regarding a drawing position is acquired by a drawing position information acquisition method according to an embodiment of the present invention. The drawing device 1 is a direct drawing device that irradiates a photosensitive material on a substrate 9 with spatially modulated substantially beam-shaped light and scans the irradiation area 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. The same applies to other figures.

[0017] The substrate 9 is, for example, a plate-like member that is roughly rectangular in plan view. The substrate 9 is, for example, a printed circuit board. On the main surfaces on both sides of the substrate 9, a resist film formed of a photosensitive material is provided on the copper layer. In the drawing apparatus 1, a circuit pattern is drawn (i.e., formed) on the resist film of the substrate 9. In the following description, one main surface of the substrate 9 will also be called the "first main surface 91," and the other main surface of the substrate 9 will also be called the "second main surface 92." The type and shape of the substrate 9 may be changed in various ways.

[0018] As shown in Figure 1, the drawing apparatus 1 comprises a stage 21, a stage moving mechanism 22, an imaging unit 3, a pattern drawing unit 4, and a control unit 10. The stage 21 is a substantially flat substrate holding unit that holds the horizontal substrate 9 from below, below the imaging unit 3 and the pattern drawing unit 4 (i.e., on the (-Z) side). The stage 21 is, for example, a vacuum chuck that holds the lower main surface (hereinafter also referred to as the "bottom surface") of the substrate 9 by suction. The stage 21 may have a structure other than a vacuum chuck, for example, a mechanical chuck. The upper main surface (hereinafter also referred to as the "top surface") of the substrate 9 placed on the stage 21 is substantially perpendicular to the Z direction and substantially parallel to the X and Y directions. In the example shown in Figure 1, the substrate 9 is placed on the stage 21 with the first main surface 91 facing upwards (i.e., on the (+Z) side).

[0019] The stage movement mechanism 22 is a movement mechanism that moves the stage 21 relative to the imaging unit 3 and the pattern drawing unit 4 in a horizontal direction (i.e., a direction substantially parallel to the upper surface of the substrate 9). The stage movement mechanism 22 comprises a first movement mechanism 23 and a second movement mechanism 24. The second movement mechanism 24 moves the stage 21 linearly in the X direction along a guide rail. The first movement mechanism 23 moves the stage 21 linearly in the Y direction along the guide rail together with the second movement mechanism 24. The drive source for the first movement mechanism 23 and the second movement mechanism 24 is, for example, a linear servo motor or a motor attached to a ball screw. The structure of the first movement mechanism 23 and the second movement mechanism 24 can be modified in various ways.

[0020] The drawing device 1 may be provided with a stage rotation mechanism that rotates the stage 21 around a rotation axis extending in the Z direction. The drawing device 1 may also be provided with a stage lifting mechanism that moves the stage 21 in the Z direction. For example, a servo motor can be used as the stage rotation mechanism. For example, a linear servo motor can be used as the stage lifting mechanism. The structures of the stage rotation mechanism and the stage lifting mechanism can be modified in various ways.

[0021] The imaging unit 3 includes a plurality of alignment cameras 31 (two in the example shown in Figure 1) arranged in the X direction. Each alignment camera 31 is supported above the stage 21 and the stage movement mechanism 22 by a gate-shaped head support 30 that spans the stage 21 and the stage movement mechanism 22. Of the two alignment cameras 31, one alignment camera 31 is fixed to the head support 30, while the other alignment camera 31 is movable in the X direction on the head support 30. This allows the distance in the X direction between the two alignment cameras 31 to be changed. The number of alignment cameras 31 in the imaging unit 3 may be one or three or more.

[0022] Each alignment camera 31 is a camera equipped with an image sensor and optical system (not shown). Each alignment camera 31 is, for example, an area camera that acquires a two-dimensional image. The image sensor is, for example, equipped with multiple image elements such as CCDs (Charge Coupled Devices) arranged in a matrix. In each alignment camera 31, reflected light from illumination light (not shown) guided to the upper surface of the substrate 9 is guided to the image sensor via the optical system. The image sensor receives the reflected light from the upper surface of the substrate 9 and acquires an image of a roughly rectangular imaging area. Various light sources such as LEDs (Light Emitting Diodes) can be used as the light source. Note that each alignment camera 31 may be a different type of camera, such as a line camera.

[0023] The pattern drawing unit 4 includes a plurality of drawing heads 41 arranged in the X and Y directions. In the example shown in Figure 1, six drawing heads 41 are arranged in a substantially linear fashion in the X direction. Each drawing head 41 is supported above the stage 21 and the stage moving mechanism 22 by a gate-shaped head support 40 that spans the stage 21 and the stage moving mechanism 22. The head support 40 is located on the (+Y) side of the head support 30 of the imaging unit 3. The number of drawing heads 41 in the pattern drawing unit 4 may be changed as appropriate. For example, the number of drawing heads 41 may be one or two or more.

[0024] Each drawing head 41 includes a light source, optical system, and spatial light modulation element (not shown). Various elements such as DMD (Digital Micro Mirror Device) and GLV (Grating Light Valve) (registered trademark of Silicon Light Machines (Sunnyvale, California)) can be used as spatial light modulation elements. Various light sources such as LD (Laser Diode) can be used as light sources. Multiple drawing heads 41 have substantially the same structure.

[0025] In the drawing device 1, modulated (i.e., spatially light-modulated) light from multiple drawing heads 41 of the pattern drawing unit 4 is irradiated onto the upper surface of the substrate 9, while the substrate 9 is moved in the Y direction by the stage moving mechanism 22. As a result, the irradiation area of ​​the light from the multiple drawing heads 41 is scanned on the substrate 9 in the Y direction, and a pattern is drawn on the substrate 9. In the following description, the Y direction will also be called the "scanning direction," and the X direction will also be called the "width direction." The stage moving mechanism 22 is a scanning mechanism that moves the irradiation area of ​​the light from each drawing head 41 on the substrate 9 in the scanning direction.

[0026] In the drawing device 1, drawing on the substrate 9 is performed using a so-called single-pass method. Specifically, the stage 21 is moved relative to the multiple drawing heads 41 in the Y direction by the stage moving mechanism 22, and the light irradiation area from the multiple drawing heads 41 is scanned only once in the Y direction (i.e., scanning direction) on the upper surface of the substrate 9. This completes the drawing on the substrate 9. In addition, the drawing device 1 may also perform drawing on the substrate 9 using a multi-pass method in which the stage 21 is moved in the Y direction and stepped in the X direction repeatedly. When multi-pass drawing is performed in the drawing device 1, the Y direction is the main scanning direction and the X direction is the sub-scanning direction. Furthermore, the first moving mechanism 23 of the stage moving mechanism 22 is a main scanning mechanism that moves the stage 21 in the main scanning direction, and the second moving mechanism 24 is a sub-scanning mechanism that moves the stage 21 in the sub-scanning direction.

[0027] Figure 2 is a plan view showing an enlarged view of the (-Y) end of the stage 21. In Figure 2, the substrate 9 on the stage 21 is drawn with a dashed line. As shown in Figure 2, the drawing apparatus 1 further comprises an alignment mark drawing unit 51. The alignment mark drawing unit 51 is positioned inside the stage 21 (i.e., between the upper and lower surfaces of the stage 21) and is fixed to the stage 21. The alignment mark drawing unit 51 draws alignment marks by irradiating light onto the lower surface of the substrate 9 held on the stage 21 so as to cover the top of the alignment mark drawing unit 51.

[0028] The alignment mark drawing unit 51 includes a plurality of markers 511. The plurality of markers 511 are arranged in the X direction near the (-Y) side edge of the stage 21. In the example shown in Figure 2, five markers 511 are arranged in a substantially straight line substantially parallel to the X direction. Of the five markers 511, the marker 511 closest to (-X) is located at the corner of the substrate 9 on both the (-X) and (-Y) sides, and the marker 511 closest to (+X) is located at the corner of the substrate 9 on both the (+X) and (-Y) sides. Of the five markers 511, the four markers 511 excluding the marker 511 closest to (-X) are arranged at substantially equal intervals in the X direction. The number and arrangement of the plurality of markers 511 can be varied. For example, the number of plurality of markers 511 may be two. Also, the plurality of markers 511 may be arranged substantially parallel to the Y direction, or they may be arranged in an L-shape in the X and Y directions.

[0029] Figure 3 is a longitudinal cross-sectional view showing one marker 511 and its vicinity. The multiple markers 511 described above have substantially the same structure. The markers 511 are housed in substantially cylindrical recesses 211 provided on the upper surface of the stage 21. The upper end opening of the recess 211 may be closed by a translucent, substantially flat cover member.

[0030] As shown in Figure 3, the marker 511 comprises a light source 512, an optical system 513, and an aperture 514. The light source 512 is located at the bottom of the recess 211 and emits light in the (+Z) direction. For example, an LED that emits ultraviolet light can be used as the light source 512. The optical system 513 is located on the (+Z) side of the light source 512 and guides the light from the light source 512 to the lower surface of the substrate 9. The optical system 513 comprises a plurality of lenses (not shown) arranged in the Z direction. The aperture 514 is located between the plurality of lenses of the optical system 513 and is a mask portion that allows only a portion of the light from the light source 512 to pass through. The aperture 514 is a substantially flat plate-shaped member provided with an opening corresponding to the alignment mark described above. The aperture 514 is formed of a metal such as stainless steel.

[0031] Figure 4 is a bottom view showing one of several alignment marks 93 drawn on the underside of the substrate 9 by multiple markers 511. The appearance of the multiple alignment marks 93 is the same as that of the others. In the example shown in Figure 4, the alignment mark 93 comprises four mark elements 931 that are circles of the same size. The four mark elements 931 are located at the four vertices of a virtual square. In other words, the four mark elements 931 are arranged in a grid in the X and Y directions. To put it another way, in the alignment mark 93, two other mark elements 931 are positioned at approximately the same location in the X direction as two mark elements 931 that are aligned in the X direction, on the (+Y) side. The distance between each pair of adjacent mark elements 931 in the X direction is approximately the same as the distance between each pair of adjacent mark elements 931 in the Y direction.

[0032] Furthermore, the shape of the mark element 931 is not limited to a circle, and may be changed in various ways, such as a triangle, rectangle, polygon with pentagons or more, ellipse, or cross. The arrangement of the mark elements 931 is not limited to a grid, and may be changed in various ways. The number of mark elements 931 can be changed in various ways, and may be 1 or 2 or more.

[0033] The control unit 10 shown in Figure 1 is, for example, a standard computer, and controls the stage movement mechanism 22, the imaging unit 3, the pattern drawing unit 4, and the alignment mark drawing unit 51, etc. The control unit 10 also has positional relationship information and correction information regarding the drawing position in the drawing device 1 stored in advance. The positional relationship information and correction information are used to align the drawing position of the pattern drawn on the upper surface of the substrate 9 by the pattern drawing unit 4 with the drawing position of the alignment mark 93 (see Figure 4) drawn on the lower surface of the substrate 9 by the alignment mark drawing unit 51 (see Figure 2).

[0034] Positional relationship information indicates the relative position in a plan view between the pattern on the upper surface of the substrate 9 and the alignment marks 93 on the lower surface of the substrate 9. Positional relationship information is calculated based on the design positions of the multiple drawing heads 41 of the pattern drawing unit 4 and the design positions of the multiple markers 511 of the alignment mark drawing unit 51. Correction information is information for correcting errors in the positional relationship information caused by the mounting accuracy of the markers 511, etc. Specifically, correction information indicates the difference between the actual position and the design position of the alignment marks 93 drawn on the lower surface of the substrate 9 by the alignment mark drawing unit 51. The method for obtaining correction information will be described later.

[0035] Next, the process of drawing a pattern onto the substrate 9 by the drawing device 1 will be explained with reference to Figures 5 and 6. Figure 5 is a diagram showing the process flow when drawing a pattern on the first main surface 91 of the substrate 9. Figure 6 is a diagram showing the process flow when drawing a pattern on the second main surface 92 of the substrate 9, after a pattern has been drawn on the first main surface 91. In the following explanation, the pattern drawn on the first main surface 91 of the substrate 9 will also be called the "first pattern," and the pattern drawn on the second main surface 92 of the substrate 9 will also be called the "second pattern."

[0036] As shown in Figure 5, when the first pattern is drawn on the first main surface 91, first, the substrate 9 with the first main surface 91 facing upwards is loaded into the drawing apparatus 1 shown in Figure 1 and held by the stage 21 (step S11). The stage 21 is located at an loading / unloading position on the (-Y) side of the imaging unit 3 and the pattern drawing unit 4. Positioning marks (hereinafter also referred to as "positioning marks"), not shown, are pre-formed on the upper surface (i.e., the first main surface 91) of the substrate 9 held on the stage 21. The positioning marks may be part of the pattern pre-drawn on the first main surface 91 of the substrate 9, or they may be marks specifically for positioning that are different from the pattern. The positioning marks have a different appearance from, for example, the alignment marks 93 described above.

[0037] Next, the stage moving mechanism 22 moves the substrate 9 together with the stage 21 in the (+Y) direction, moving it below the imaging unit 3. The imaging unit 3 then images the positioning marks provided on the upper surface of the substrate 9 (i.e., the first main surface 91), and the acquired image is sent to the control unit 10. In the control unit 10, pattern matching is performed on the image output from the imaging unit 3 using a reference image to determine the position of the positioning marks in the image. The position of the substrate 9 on the stage 21 is then detected (step S12). The above pattern matching is performed by, for example, a known pattern matching method (e.g., geometric shape pattern matching or normalized correlation search).

[0038] The position of the substrate 9 detected in step S12 includes the coordinates of the substrate 9 in the X and Y directions on the stage 21, as well as the orientation of the substrate 9. Based on the detected position of the substrate 9, the control unit 10 adjusts the drawing data for the first main surface 91 of the substrate 9 (i.e., performs alignment processing).

[0039] Next, the control unit 10 controls the stage movement mechanism 22 and the pattern drawing unit 4, so that the modulated light described above is irradiated onto the upper surface (i.e., the first main surface 91) of the substrate 9, which is moved relative to the drawing head 41 of the pattern drawing unit 4 in the Y direction, and the first pattern is drawn on the first main surface 91 of the substrate 9 (step S13). In step S13, the first pattern is drawn based on the drawing data adjusted in step S12. In other words, in step S13, the modulation interval and modulation timing of the light beam irradiated from the pattern drawing unit 4 to the substrate 9, as well as the scanning position of the light beam on the first main surface 91 of the substrate 9, are mechanically and automatically corrected using a known correction method based on the position of the substrate 9 detected in step S12. As a result, the first pattern can be drawn on the first main surface 91 with high positional accuracy.

[0040] In the drawing apparatus 1, the alignment mark drawing unit 51 and the like are controlled by the control unit 10 to draw alignment marks 93 on the lower surface (i.e., the second main surface 92) of the substrate 9 on the stage 21 (step S14). The drawing of alignment marks 93 on the second main surface 92 (step S14) may be performed in parallel with the drawing of the first pattern on the first main surface 91 (step S13) as described above, or it may be performed before or after the drawing of the first pattern. When steps S11 to S14 are completed, the substrate 9 is removed from the stage 21 of the drawing apparatus 1.

[0041] As shown in Figure 6, when a second pattern is drawn on the second main surface 92 of a substrate 9 on which a first pattern has been drawn on the first main surface 91, the substrate 9, with its second main surface 92 facing upwards, is first loaded into the drawing apparatus 1 shown in Figure 1 and held by the stage 21 (step S21). The stage 21 is located in the loading / unloading position described above. The above-mentioned multiple alignment marks 93 are provided on the upper surface (i.e., the second main surface 92) of the substrate 9 held on the stage 21.

[0042] Next, the stage moving mechanism 22 moves the substrate 9 together with the stage 21 in the (+Y) direction, and it moves below the imaging unit 3. Then, the alignment marks 93 provided on the upper surface of the substrate 9 (i.e., the second main surface 92) are imaged, and the acquired image is sent to the control unit 10. In the control unit 10, pattern matching similar to the above is performed on the image output from the imaging unit 3, and the position of the alignment marks 93 in the image is determined.

[0043] Then, based on the detected alignment mark 93 position and the positional relationship information and correction information described above, the position of the first pattern on the first main surface 91 of the substrate 9 in a plan view (i.e., the relative position of the first pattern with respect to the drawing head 41) is determined (step S22). Specifically, the design relative position of the first pattern with respect to the drawing head 41 (i.e., the relative position assuming there are no errors due to the mounting accuracy of the marker 511, etc.) is determined from the detected alignment mark 93 position and the positional relationship information described above. Then, the actual relative position of the first pattern with respect to the drawing head 41 is determined by correcting this design relative position based on the correction information described above. The control unit 10 adjusts the drawing data for the second main surface 92 of the substrate 9 (i.e., performs alignment processing) based on the actual relative position of the first pattern with respect to the drawing head 41.

[0044] Next, the control unit 10 controls the stage movement mechanism 22 and the pattern drawing unit 4, so that the modulated light described above is irradiated onto the upper surface (i.e., the second main surface 92) of the substrate 9, which is moved relative to the drawing head 41 of the pattern drawing unit 4 in the Y direction, and the second pattern is drawn on the second main surface 92 of the substrate 9 (step S23). In step S23, the second pattern is drawn based on the drawing data adjusted in step S22. In other words, in step S23, the modulation interval and modulation timing of the light beam irradiated from the pattern drawing unit 4 to the substrate 9, as well as the scanning position of the light beam on the second main surface 92 of the substrate 9, are mechanically and automatically corrected using a known correction method based on the output from the imaging unit 3, as well as the positional relationship information and correction information described above. This improves the relative positional accuracy between the second pattern drawn on the second main surface 92 of the substrate 9 and the first pattern already drawn on the first main surface 91. Furthermore, when drawing the second pattern on the second main surface 92 of the substrate 9, it is not necessary to draw alignment marks on the first main surface 91 (i.e., the bottom surface of the substrate 9).

[0045] In the drawing device 1, for example, steps S11 to S14 are performed sequentially on multiple substrates 9, and then steps S21 to S23 are performed sequentially on the same multiple substrates 9. Alternatively, in the drawing device 1, steps S11 to S14 and steps S21 to S23 may be performed consecutively on a single substrate 9.

[0046] Next, the method for acquiring the correction information described above will be explained. Figure 7 is a plan view showing the correction substrate 8 used to acquire the correction information. Figure 8 is a bottom view showing the correction substrate 8. The correction substrate 8 is, for example, a flat plate-shaped member that is roughly rectangular in plan view. The area of ​​the correction substrate 8 is smaller than the area of ​​the substrate 9. In the examples shown in Figures 7 and 8, the size of the correction substrate 8 in the X direction is greater than or equal to the size of the substrate 9 in the X direction. Also, the size of the correction substrate 8 in the Y direction is smaller than the size of the substrate 9 in the Y direction. In other words, the correction substrate 8 is a flat plate-shaped member that is roughly rectangular in shape and long in the X direction (i.e., the direction of arrangement of the multiple markers 511 described above). In the following explanation, one main surface of the correction substrate 8 in Figure 7 that faces the (+Z) side will also be called the "first main surface 81", and the other main surface that faces the (-Z) side will also be called the "second main surface 82".

[0047] The correction substrate 8 is formed from, for example, metal or resin. A photosensitive dry film is laminated to the first main surface 81 and the second main surface 82 of the correction substrate 8. The thickness of the correction substrate 8 may be the same as or different from the thickness of the substrate 9. The correction substrate 8 is discarded after being used to acquire the correction information described later. In other words, the correction substrate 8 is a disposable substrate.

[0048] Two through holes 83 are provided at both ends of the correction substrate 8 in the X direction. The positions of the two through holes 83 in the Y direction are approximately the same. In other words, the two through holes 83 are aligned in the X direction. The shapes of the two through holes 83 may be the same or different. In this embodiment, the shapes of the two through holes 83 are the same. Each through hole 83 is approximately a disc shape centered on a central axis extending in the Z direction. The shape of the cross-section of the through hole 83 perpendicular to the Z direction is approximately the same at any position in the Z direction.

[0049] In the correction substrate 8 illustrated in Figures 7 and 8, the opening 831 on the first main surface 81 of each through-hole 83 is used as a first reference mark when acquiring correction information. In addition, the opening 832 on the second main surface 82 of each through-hole 83 is used as a second reference mark when acquiring correction information. When the correction substrate 8 is viewed from the (+Z) side, the positions of the two openings 831 in a plan view coincide with the positions of the two openings 832 in a plan view.

[0050] Figure 9 shows the flow of acquiring correction information. In acquiring correction information, first, the correction substrate 8 described above is prepared by being formed in advance (step S31). Next, the correction substrate 8, with the first main surface 81 facing upwards (i.e., (+Z) side), is brought into the drawing device 1 and held by the stage 21 (step S32). As shown in Figure 10, the correction substrate 8 is positioned to cover all of the multiple markers 511 of the alignment mark drawing section 51 provided on the stage 21.

[0051] Next, the correction substrate 8 is moved in the (+Y) direction together with the stage 21 by the stage moving mechanism 22 (see Figure 1), and moves below the imaging unit 3. Then, the imaging unit 3 takes an image of the upper surface (i.e., the first main surface 81) of the correction substrate 8, and the acquired image is sent to the control unit 10. In the control unit 10, based on the image output from the imaging unit 3, the positions of the openings 831 of the two through holes 83 (i.e., the two first reference marks) on the first main surface 81 of the correction substrate 8 are acquired (step S33). The positions of the two openings 831 are represented, for example, in an (X,Y) coordinate system with the corners on the (-X) and (-Y) sides of the stage 21 as the origin.

[0052] In the drawing device 1, the alignment mark drawing unit 51 is controlled by the control unit 10 to draw a plurality of alignment marks 93 (see Figure 4) on the lower surface (i.e., the second main surface 82) of the correction substrate 8 on the stage 21 (step S34). The drawing of the alignment marks 93 on the second main surface 82 (step S34) may be performed in parallel with the acquisition of the position of the opening 831 (step S33) described above, or it may be performed before or after said position acquisition.

[0053] When steps S33 to S34 are completed, the stage movement mechanism 22 is controlled by the control unit 10, and the stage 21 is moved to the loading / unloading position. The correction substrate 8 is then flipped left and right (i.e., flipped around a virtual axis of rotation extending in the Y direction at the center of the correction substrate 8 in the X direction), and as shown in Figure 11, it is held by the stage 21 with the second main surface 82 facing upwards (i.e., (+Z) side) (step S35). In the state shown in Figure 11, the through hole 83 on the right side (i.e., (+X) side) of Figure 10 is located at the left end (i.e., (-X) side) of the correction substrate 8, and the through hole 83 on the left side in Figure 10 is located at the right end of the correction substrate 8. Note that in Figure 11, the multiple alignment marks 93 drawn on the second main surface 82 are drawn larger than they actually are.

[0054] Next, the correction substrate 8 is moved in the (+Y) direction together with the stage 21 by the stage moving mechanism 22 (see Figure 1), and moves below the imaging unit 3. The imaging unit 3 then images the upper surface (i.e., the second main surface 82) of the correction substrate 8, and the acquired image is sent to the control unit 10. In the control unit 10, based on the image output from the imaging unit 3, the positions of the openings 832 of the two through holes 83 (i.e., the two second reference marks) on the second main surface 82 of the correction substrate 8 are acquired. The positions of the multiple alignment marks 93 drawn on the second main surface 82 of the correction substrate 8 are also acquired (step S36). The positions of the two openings 832 and the multiple alignment marks 93 are represented in an (X,Y) coordinate system with the (-X) and (-Y) corners of the stage 21 as the origin, similar to the opening 831.

[0055] As described above, the multiple markers 511 (see Figure 10) of the alignment mark drawing unit 51 are arranged substantially parallel to the X direction. Therefore, the multiple alignment marks 93 drawn on the second main surface 82 of the correction substrate 8 are also arranged in an arrangement direction substantially parallel to the X direction. Note that if the correction substrate 8 is placed on the stage 21 at a slight incline, the arrangement direction of the multiple alignment marks 93 captured by the imaging unit 3 in step S36 is in a direction along the X direction while being slightly inclined with respect to the X direction. In the example shown in Figure 11, the distance between the openings 832 of the two through holes 83 in that arrangement direction (i.e., the distance between the two openings 831 in that arrangement direction) is greater than or equal to the distance between the two alignment marks 93 located at both ends of that arrangement direction among the multiple alignment marks 93.

[0056] When step S36 is completed, the above-mentioned correction information is obtained based on the positions of the two openings 831 (i.e., the two first reference marks) acquired in step S33, as well as the positions of the two openings 832 (i.e., the two second reference marks) and the positions of the multiple alignment marks 93 acquired in step S36 (step S37). This correction information is a type of drawing position information relating to the drawing positions of the multiple alignment marks 93 by the alignment mark drawing unit 51, and as described above, it shows the difference between the design positions of the multiple alignment marks 93 and the actual drawing positions of the multiple alignment marks 93 by the alignment mark drawing unit 51.

[0057] Specifically, for example, based on the position information acquired in step S33, a vector (hereinafter also referred to as the "first reference vector") is determined that points from the opening 831 of one through-hole 83 to the opening 831 of the other through-hole 83. Next, based on the position information acquired in step S36, a vector (hereinafter also referred to as the "second reference vector") is determined that points from the opening 832 of one through-hole 83 to the opening 832 of the other through-hole 83. Then, by comparing the first reference vector with a vector obtained by inverting the second reference vector with respect to the X direction (i.e., a vector with the sign of the X component of the second reference vector reversed), the difference (hereinafter also referred to as the "shift angle") between the orientation of the correction substrate 8 imaged in step S32 and the orientation of the correction substrate 8 imaged in step S35 is determined.

[0058] Next, from the position information acquired in step S36, multiple vectors (hereinafter also referred to as "mark vectors") are obtained that point from the opening 832 of one of the through holes 83 to each of the multiple alignment marks 93. These multiple mark vectors are then inverted and rotated by the aforementioned shift angle to obtain multiple correction mark vectors. Then, based on the position of the opening 831 of one of the through holes 83 acquired in step S33 (for example, the position in an (X,Y) coordinate system with the (-X) and (-Y) corners of the stage 21 as the origin) and the multiple correction mark vectors, the relative positions of the multiple alignment marks 93 drawn on the lower surface of the substrate 9 with respect to the stage 21 are determined. Subsequently, the relative positions of the multiple alignment marks 93 (i.e., the actual relative positions) are compared with the design relative positions, and the difference between the actual relative positions and the design relative positions is obtained as correction information.

[0059] In the above example, the correction information described above is acquired as drawing position information in step S37, but this is not limited to this. The drawing position information may also be other information, such as the actual relative positions of the multiple alignment marks 93 drawn on the lower surface of the substrate 9 with respect to the stage 21.

[0060] As described above, the drawing apparatus 1 comprises a stage 21, a stage moving mechanism 22, an imaging unit 3, a pattern drawing unit 4, and an alignment mark drawing unit 51. The stage 21 holds the substrate 9. The stage moving mechanism 22 moves the stage 21 horizontally. The imaging unit 3 images the upper surface of the substrate 9 held on the stage 21. The pattern drawing unit 4 draws a pattern by irradiating light onto the upper surface of the substrate 9 held on the stage 21. The alignment mark drawing unit 51 is fixed to the stage 21. The alignment mark drawing unit 51 irradiates light onto the lower surface of the substrate held on the stage 21 and draws a plurality of alignment marks 93 that serve as references for the drawing position when drawing a pattern on the lower surface.

[0061] The drawing position information acquisition method for acquiring drawing position correction information in the drawing device 1 described above includes the steps of: preparing a correction substrate 8 having two first reference marks (in the example above, the openings 831 of the through holes 83) on the first main surface 81 and two second reference marks (in the example above, the openings 832 of the through holes 83) on the second main surface 82 whose positions in a plan view coincide with the two first reference marks (step S31); arranging the correction substrate 8 with the first main surface 81 facing upward so as to cover the alignment mark drawing unit 51 and holding it with the stage 21 (step S32); imaging the first main surface 81 of the correction substrate 8 with the imaging unit 3 to acquire the positions of the two first reference marks (step S33); and placing the alignment mark drawing unit 51 on the second main surface 82 of the correction substrate 8. Therefore, the process includes the steps of drawing multiple alignment marks 93 (step S34), holding the correction substrate 8 with the second main surface 82 facing upwards by the stage 21 after step S34 (step S35), imaging the second main surface 82 of the correction substrate 8 with the imaging unit 3 to acquire the positions of two second reference marks and the positions of multiple alignment marks 93 (step S36), and acquiring drawing position information regarding the drawing positions of the multiple alignment marks 93 by the alignment mark drawing unit 51 based on the positions of two first reference marks acquired in step S33 and the positions of two second reference marks and multiple alignment marks 93 acquired in step S36 (step S37). As a result, as described above, the relative positional accuracy of the patterns drawn on the main surfaces on both sides of the substrate 9 in the drawing apparatus 1 can be improved.

[0062] As described above, the drawing position information acquired in step S37 is preferably correction information indicating the difference between the design position of the multiple alignment marks 93 and the drawing position of the multiple alignment marks 93 by the alignment mark drawing unit 51. This makes it possible to suitably improve the relative positional accuracy of the patterns drawn on the main surfaces on both sides of the substrate 9.

[0063] As described above, it is preferable that the two first reference marks are openings 831 on the first main surface 81 of the two through holes 83 provided in the correction substrate 8, and the two second reference marks are openings 832 on the second main surface 82 of the two through holes 83. This makes it easy to form a correction substrate 8 with first and second reference marks whose positions coincide in a plan view. As a result, the preparation of the correction substrate 8 in step S31 can be made easier.

[0064] As described above, it is preferable that the multiple alignment marks 93 are arranged along a predetermined direction. Furthermore, it is preferable that the distance between two first reference marks in the direction of arrangement is greater than or equal to the distance between two alignment marks 93 located at both ends of that direction. This allows for accurate acquisition of the positional relationship between the two first reference marks. As a result, the drawing position information described above can be acquired with high accuracy.

[0065] As described above, the drawing method for drawing a pattern on the substrate 9 includes the steps of: holding the substrate 9 with one main surface (first main surface 91 in the above example) facing upwards using the stage 21 (step S11); capturing positioning marks on the one main surface with the imaging unit 3, performing alignment processing on the substrate 9 based on the output from the imaging unit 3, and drawing a pattern (first pattern in the above example) on the one main surface with the pattern drawing unit 4 (steps S12-S13); and drawing multiple patterns on the other main surface of the substrate 9 (second main surface 92 in the above example) with the alignment mark drawing unit 51. The process includes the steps of drawing alignment marks 93 (step S14), holding the substrate 9 with the other main surface facing upwards using the stage 21 (step S21), and capturing a plurality of alignment marks 93 on the other main surface with the imaging unit 3, performing alignment processing on the substrate 9 based on the output from the imaging unit 3 and the correction information acquired by the drawing position information acquisition method described above, and drawing a pattern (the second pattern in the above example) on the other main surface using the pattern drawing unit 4 as a reference (steps S22-S23). This makes it possible to improve the relative positional accuracy of the patterns drawn on the main surfaces on both sides of the substrate 9, as described above.

[0066] The drawing position information acquisition method described above can also be applied, for example, to acquiring correction information in a twin-stage type drawing device. Figure 12 is a perspective view showing a twin-stage type drawing device 1a. In addition to the components of the drawing device 1 described above, the drawing device 1a further comprises another stage 21a and another stage moving mechanism 22a. The stage 21a and the stage moving mechanism 22a are arranged adjacent to the stage 21 and the stage moving mechanism 22 on the (+X) side of the stage 21 and the stage moving mechanism 22. The stage 21a and the stage moving mechanism 22a each have substantially the same structure as the stage 21 and the stage moving mechanism 22. The stage 21a holds the substrate 9 substantially the same as the stage 21. The stage moving mechanism 22a moves the stage 21a horizontally substantially the same as the stage moving mechanism 22.

[0067] In addition to the alignment camera 31 described above, the imaging unit 3 of the drawing device 1a further includes a camera movement mechanism 32a that moves the alignment camera 31 in the X direction. The camera movement mechanism 32a moves the multiple alignment cameras 31 between a first imaging position above the stage movement mechanism 22 and a second imaging position above the stage movement mechanism 22a.

[0068] The pattern drawing unit 4 of the drawing device 1a further includes a drawing head moving mechanism 42a that moves the drawing head 41 in the X direction, in addition to the drawing head 41 described above. The drawing head moving mechanism 42a moves the multiple drawing heads 41 between a first drawing position above the stage moving mechanism 22 and a second drawing position above the stage moving mechanism 22a.

[0069] Figure 13 is a plan view showing an enlarged view of the (-Y) end of the stage 21a. In Figure 13, the substrate 9 on the stage 21a is drawn with a dashed line. As shown in Figure 13, the drawing apparatus 1a further comprises another alignment mark drawing unit 51a. The alignment mark drawing unit 51a is fixed to the stage 21a. The structure of the alignment mark drawing unit 51a is substantially the same as that of the alignment mark drawing unit 51 fixed to the stage 21. The alignment mark drawing unit 51a irradiates light onto the lower surface of the substrate 9 held on the stage 21a and draws a plurality of alignment marks that serve as a reference for the drawing position when drawing a pattern on the lower surface.

[0070] The alignment mark drawing unit 51a includes a plurality of markers 511a. The plurality of markers 511a are arranged in the X direction near the (-Y) side edge of the stage 21a. The structure and arrangement of the plurality of markers 511a are substantially the same as those of the plurality of markers 511 of the alignment mark drawing unit 51 described above (see Figure 2). In the example shown in Figure 13, five markers 511a are arranged in a substantially straight line substantially parallel to the X direction. Of the five markers 511a, the marker 511a furthest to (-X) is located at the (-X) and (-Y) corners of the substrate 9, and the marker 511a furthest to (+X) is located at the (+X) and (-Y) corners of the substrate 9. Of the five markers 511a, the four markers 511 excluding the marker 511a furthest to (-X) are arranged at substantially equal intervals in the X direction. The number and arrangement of the multiple markers 511a can be varied. For example, the number of multiple markers 511a may be two. Also, the multiple markers 511a may be arranged substantially parallel to each other in the Y direction, or they may be arranged in an L-shape in the X and Y directions.

[0071] Figure 14 is a bottom view showing one of several alignment marks 94 drawn on the underside of the substrate 9 by multiple markers 511a. The appearance of these multiple alignment marks 94 is the same as that of the others. Also, the appearance of the alignment mark 94 is different from the appearance of the alignment mark 93 shown in Figure 4. In the example shown in Figure 14, the alignment mark 94 comprises four mark elements 941 that are circles of the same size. The shape and size of each mark element 941 are the same as the mark element 931 described above. The alignment mark 94 has the appearance of the alignment mark 93 rotated by approximately 45° around a rotation axis that points in the Z direction. That is, the alignment mark 94 is similar in shape to the alignment mark 93. Similarity here means that in two figures, rotating one figure and / or scaling it (i.e., scaling it by equal magnitude in the X and Y directions) will result in it matching the other figure.

[0072] In the alignment mark 94 illustrated in Figure 14, one mark element 941 is placed on the (-X) side, and another mark element 941 is placed on the (+X) side. These two mark elements 941 are placed at approximately the same position in the Y direction. In addition, two other mark elements 941 are placed side by side in the Y direction between these two mark elements 941 in the X direction. These two other mark elements 941 are placed on the (+Y) and (-Y) sides, respectively, of the two mark elements 941 on the (+X) side and the (-X) side. Note that the shape of the mark elements 941 is not limited to circles, but can be changed in various ways, such as triangles, rectangles, polygons with pentagons or more, ellipses, or cross shapes. Also, the arrangement and number of mark elements 941 can be changed in various ways.

[0073] As described above, alignment marks 93 and 94 are the same in shape and size, differing only in their orientation on the substrate 9. Therefore, the marker 511a of the alignment mark drawing unit 51a can use a component of the same shape as the aperture 514 (see Figure 3) of the marker 511 of the alignment mark drawing unit 51 (i.e., a component with the same number, shape, size, and arrangement of openings), simply by changing the mounting orientation. Consequently, the manufacturing of the drawing device 1a can be simplified, and the manufacturing cost of the drawing device 1a can be reduced.

[0074] In the drawing device 1a, the alignment mark 93 drawn by the alignment mark drawing unit 51 and the alignment mark 94 drawn by the alignment mark drawing unit 51a may be dissimilar in shape. Dissimilar in shape means that even if one of the two figures is rotated and / or scaled as described above, it cannot match the other figure. For example, if the alignment mark 93 has the four mark elements 931 described above, and the alignment mark 94 has only three of the four mark elements 941 described above, then the alignment mark 93 and the alignment mark 94 are dissimilar in shape.

[0075] The pattern drawing on the substrate 9 in the drawing apparatus 1a shown in Figure 12 is performed, for example, as follows. When the first pattern is drawn on the first main surface 91 of the substrate 9 in the drawing apparatus 1a, first the substrate 9 is brought into the drawing apparatus 1a and held by the stage 21 with the first main surface 91 facing upwards (Figure 5: Step S11). Subsequently, the alignment camera 31 located at the first imaging position captures the positioning marks on the first main surface 91 of the substrate 9 and performs alignment processing (Step S12). When the alignment processing is completed, the alignment camera 31 is moved from the first imaging position to the second imaging position. Then, as the stage 21 moves in the Y direction by the stage moving mechanism 22, light is shone from the drawing head 41 located at the first drawing position onto the first main surface 91 of the substrate 9, and the first pattern is drawn. At the same time, light is shone from the alignment mark drawing unit 51 (see Figure 2), which is fixed to the stage 21, onto the second main surface 92 of the substrate 9, and alignment marks 93 (see Figure 4) are drawn (steps S13 to S14).

[0076] In addition, in the drawing apparatus 1a, in parallel with steps S13 to S14 (i.e., drawing on the substrate 9 on the stage 21), another substrate 9 is brought in and held by the stage 21a with its first main surface 91 facing upwards. The alignment camera 31, located at the second imaging position, captures the positioning marks on the first main surface 91 of the other substrate 9 and performs alignment processing (steps S11 to S12). Once the alignment processing is completed, the alignment camera 31 is moved to the first imaging position.

[0077] Furthermore, once the drawing of the first pattern on the substrate 9 on the stage 21 is completed, the drawing head 41 is moved from the first drawing position to the second drawing position. Then, light is shone from the drawing head 41 located at the second drawing position onto the first main surface 91 of the substrate 9 on the stage 21a, which is moved in the Y direction by the stage moving mechanism 22a, to draw the first pattern. At the same time, light is shone from the alignment mark drawing unit 51a (see Figure 13), which is fixed to the stage 21a, onto the second main surface 92 of the substrate 9, to draw alignment marks 94 (see Figure 14) (steps S13 to S14).

[0078] In the drawing apparatus 1a, in parallel with steps S13 to S14 (i.e., drawing on the substrate 9 on stage 21a), the substrate 9 on stage 21 is removed, and a new substrate 9 is brought in and held by stage 21. Then, steps S11 to S14 are performed alternately and partially in parallel on the substrate 9 on stage 21 and the substrate 9 on stage 21a.

[0079] In the drawing apparatus 1a, when a second pattern is drawn on the second main surface 92 of the substrate 9, first the substrate 9 is brought into the drawing apparatus 1a and held by the stage 21 with the second main surface 92 facing upwards (Figure 6: step S21). Subsequently, the alignment camera 31 located at the first imaging position captures the alignment marks 93 (see Figure 4) on the second main surface 92 of the substrate 9, and alignment processing is performed based on the positional relationship information and correction information described above (step S22). The positional relationship information and correction information relate to the alignment mark drawing unit 51 fixed to the stage 21, and the correction information is acquired in advance by steps S31 to S37 (see Figure 9) described above.

[0080] Once the alignment process described above is complete, the alignment camera 31 is moved from the first imaging position to the second imaging position. Then, light is shone from the drawing head 41 located at the first drawing position onto the second main surface 92 of the substrate 9 on the stage 21, which is moved in the Y direction by the stage moving mechanism 22, and the second pattern is drawn (step S23).

[0081] Furthermore, in the drawing apparatus 1a, in parallel with step S23 (i.e., drawing on the substrate 9 on the stage 21), another substrate 9 is brought in and held by the stage 21a with its second main surface 92 facing upwards. At the same time, the alignment camera 31 located at the second imaging position captures the alignment marks 94 (see Figure 14) on the second main surface 92 of the other substrate 9, and alignment processing is performed based on positional relationship information and correction information related to the alignment mark drawing unit 51a fixed to the stage 21a (steps S21 to S22). Once the alignment processing is completed, the alignment camera 31 is moved to the first imaging position.

[0082] Furthermore, once the drawing of the second pattern on the substrate 9 on the stage 21 is completed, the drawing head 41 is moved from the first drawing position to the second drawing position. Then, light is shone from the drawing head 41 located at the second drawing position onto the second main surface 92 of the substrate 9 on the stage 21a, which is being moved in the Y direction by the stage moving mechanism 22a, and the second pattern is drawn (step S23).

[0083] In the drawing apparatus 1a, in parallel with step S23 (i.e., drawing on the substrate 9 on stage 21a), the substrate 9 on stage 21 is removed, and a new substrate 9 is brought in and held by stage 21. Then, steps S21 to S23 described above are performed alternately and partially in parallel on the substrate 9 on stage 21 and the substrate 9 on stage 21a.

[0084] Correction information relating to the alignment mark drawing unit 51a fixed to the stage 21a described above is acquired using the correction substrate 8 described above, on which alignment marks 93 (see Figure 4) are drawn on the second main surface 82, in substantially the same manner as in steps S31 to S37 (see Figure 9), and stored in the control unit 10.

[0085] Figure 15 shows the flow of acquiring correction information related to the alignment mark drawing unit 51a. First, the correction substrate 8, with its second main surface 82 facing upwards (i.e., (+Z) side), is placed on the stage 21a so as to cover all of the multiple markers 511a of the alignment mark drawing unit 51a, as shown in Figure 16, and is held by the stage 21a (step S41). Next, the second main surface 82 of the correction substrate 8 is imaged by the imaging unit 3, and the positions of the openings 832 of the two through holes 83 (i.e., the two second reference marks) are acquired based on the acquired image (step S42). Note that there are multiple alignment marks 93 drawn on the second main surface 82 of the correction substrate 8 during the acquisition of correction information related to the alignment mark drawing unit 51 (steps S31 to S37), but the positions of these alignment marks 93 do not need to be acquired. In Figure 16, the multiple alignment marks 93 are drawn larger than they actually are.

[0086] Furthermore, multiple alignment marks 94 are drawn on the lower surface (i.e., the first main surface 81) of the correction substrate 8 on the stage 21a (step S43). The drawing of the alignment marks 94 on the first main surface 81 (step S43) may be performed in parallel with the acquisition of the position of the opening 832 (step S42) described above, or it may be performed before or after said position acquisition.

[0087] When steps S42 to S43 are completed, the correction substrate 8 is flipped left and right (i.e., flipped around a virtual axis of rotation extending in the Y direction at the center of the correction substrate 8 in the X direction), and is held by the stage 21a with the first main surface 81 facing upwards, as shown in Figure 17 (step S44). In the state shown in Figure 17, the through hole 83 on the right side (i.e., the (+X) side) in Figure 16 is located at the left end (i.e., the (-X) side) of the correction substrate 8, and the through hole 83 on the left side in Figure 16 is located at the right end of the correction substrate 8. Note that in Figure 17, the multiple alignment marks 94 drawn on the first main surface 81 are drawn larger than they actually are.

[0088] Next, the imaging unit 3 takes an image of the upper surface (i.e., the first main surface 81) of the correction substrate 8, and based on the acquired image, the positions of the openings 831 of the two through holes 83 (i.e., the two first reference marks) on the first main surface 81 of the correction substrate 8 are obtained. The positions of the multiple alignment marks 94 drawn on the correction substrate 8 are also obtained (step S45).

[0089] As described above, the multiple markers 511a of the alignment mark drawing unit 51a are arranged substantially parallel to the X direction. Therefore, the multiple alignment marks 94 drawn on the first main surface 81 of the correction substrate 8 are also arranged in an arrangement direction substantially parallel to the X direction. Note that if the correction substrate 8 is placed on the stage 21a at a slight incline, the arrangement direction of the multiple alignment marks 94 imaged by the imaging unit 3 in step S45 is in a direction along the X direction while being slightly inclined with respect to the X direction. In the example shown in Figure 17, the distance between the openings 831 of the two through holes 83 in the arrangement direction (i.e., the distance between the two openings 832 in the arrangement direction) is greater than or equal to the distance between the two alignment marks 94 located at both ends of the arrangement direction among the multiple alignment marks 94.

[0090] When step S45 is completed, the above-mentioned correction information for the alignment mark drawing unit 51a is acquired based on the positions of the two openings 832 (i.e., the two second reference marks) acquired in step S42, and the positions of the two openings 831 (i.e., the two first reference marks) and the positions of the multiple alignment marks 94 acquired in step S45 (step S46). This correction information is a type of drawing position information relating to the drawing positions of the multiple alignment marks 94 by the alignment mark drawing unit 51a, and indicates the discrepancy between the design positions of the multiple alignment marks 94 and the actual drawing positions of the multiple alignment marks 94 by the alignment mark drawing unit 51a. The specific method for acquiring this correction information is substantially the same as the specific method for acquiring the correction information for the alignment mark drawing unit 51 described above, except that the uses of the first main surface 81 and the second main surface 82 of the correction substrate 8 are reversed.

[0091] In the above example, the correction information described above is acquired as drawing position information in step S46, but this is not limited to this. The drawing position information may also be other information, such as the actual relative positions of the multiple alignment marks 94 drawn on the lower surface of the substrate 9 with respect to the stage 21a.

[0092] The pattern drawing in the drawing apparatus 1a shown in Figure 12 is not limited to the above example and can be modified in various ways. For example, in the drawing apparatus 1a, a substrate 9 on which alignment marks 93 have been drawn on the second main surface 92 may be held by the stage 21a with the second main surface 92 facing upwards, and a second pattern may be drawn on the second main surface 92 on the stage 21a. In this case, in the alignment process of the substrate 9 held by the stage 21a, positional relationship information and correction information relating to the alignment mark drawing unit 51 fixed to the stage 21 are used.

[0093] Furthermore, for example, in the drawing apparatus 1a, the substrate 9 on which alignment marks 94 have been drawn on the second main surface 92 is held by the stage 21a with the second main surface 92 facing upwards, and a second pattern may be drawn on the second main surface 92 on the stage 21. In this case, in the alignment process of the substrate 9 held by the stage 21, positional relationship information and correction information relating to the alignment mark drawing unit 51a fixed to the stage 21a are used.

[0094] As described above, the drawing device 1a further comprises, in addition to the configuration of the drawing device 1 described above, another stage 21a, another stage moving mechanism 22a, and another alignment mark drawing unit 51a. The stage 21a holds the substrate 9. The stage moving mechanism 22a moves the stage 21a horizontally. The alignment mark drawing unit 51a is fixed to the stage 21a. The alignment mark drawing unit 51a irradiates light onto the lower surface (second main surface 92 in the above example) of the substrate 9 held by the stage 21a and draws a plurality of other alignment marks 94 that serve as references for the drawing position when drawing a pattern (second pattern in the above example) on the lower surface.

[0095] The pattern drawing unit 4 also includes a drawing head 41 and a drawing head moving mechanism 42a. The drawing head 41 emits light downwards. The drawing head moving mechanism 42a moves the drawing head 41 between a first drawing position above the stage moving mechanism 22 and a second drawing position above another stage moving mechanism 22a. The imaging unit 3 includes an alignment camera 31 and a camera moving mechanism 32a. The camera moving mechanism 32a moves the alignment camera 31 between a first imaging position above the stage moving mechanism 22 and a second imaging position above another stage moving mechanism 22a.

[0096] The method for acquiring drawing position information for the drawing device 1a, in addition to the drawing position information acquisition method described above (steps S31 to S37), includes the steps of: holding the correction substrate 8, with its second main surface 82 facing upward, by the stage 21a, with the correction substrate 8 positioned so as to cover the alignment mark drawing unit 51a (step S41); imaging the second main surface 82 of the correction substrate 8 with the imaging unit 3 to acquire the positions of two second reference marks (in the above example, the openings 832 of the two through holes 83) (step S42); drawing a plurality of alignment marks 94 on the first main surface 81 of the correction substrate 8 with the alignment mark drawing unit 51a (step S43); and, after step S43, with the first main surface 81 facing upward The system further comprises the steps of: holding the correction substrate 8 with the stage 21a (step S44); imaging the first main surface 81 of the correction substrate 8 with the imaging unit 3 to acquire the positions of two first reference marks (in the above example, the openings 831 of the two through holes 83) and the positions of a plurality of alignment marks 94 (step S45); and acquiring another drawing position information regarding the drawing position of the plurality of alignment marks 94 by the alignment mark drawing unit 51a based on the positions of two second reference marks acquired in step S42, and the positions of the two first reference marks and the plurality of alignment marks 94 acquired in step S45 (step S46).

[0097] As a result, in a twin-stage type drawing device 1a, drawing position information for both stages 21 and 21a (i.e., drawing position information for the alignment mark drawing unit 51 and drawing position information for the alignment mark drawing unit 51a) can be acquired using a single correction substrate 8.

[0098] As described above, it is preferable that the other drawing position information acquired in step S46 is another correction information indicating the difference between the design position of the multiple alignment marks 94 and the drawing position of the multiple alignment marks 94 by the alignment mark drawing unit 51a. This makes it possible to suitably improve the relative positional accuracy of the patterns drawn on the main surfaces on both sides of the substrate 9 in the twin-stage type drawing apparatus 1a.

[0099] As described above, it is preferable that the appearance of the multiple alignment marks 93 is the same as that of the other. It is also preferable that the appearance of the multiple alignment marks 94 is the same as that of the other, and different from that of the multiple alignment marks 93. This makes it easy to determine, in the twin-stage type drawing apparatus 1a, which of the stages 21 and 21a performed the drawing of the first pattern on the first main surface 91 of the substrate 9.

[0100] It is also preferable that alignment marks 93 and 94 are non-similar in shape. This helps to prevent misidentification of alignment marks 93 and 94 even when the template is rotated or scaled during the pattern matching process described above, and allows for accurate identification of the type of alignment mark.

[0101] The drawing position information acquisition method and drawing method described above can be modified in various ways.

[0102] For example, the distance between two through holes 83 in the correction substrate 8 does not necessarily have to be greater than or equal to the distance between two alignment marks 93 located at both ends of a plurality of alignment marks 93; it may be less than that distance. Similarly, the distance between two through holes 83 in the correction substrate 8 does not necessarily have to be greater than or equal to the distance between two alignment marks 94 located at both ends of a plurality of alignment marks 94; it may be less than that distance.

[0103] The shape of the through-holes 83 in the correction substrate 8 in a plan view does not necessarily have to be circular and may be changed as appropriate. Also, the number of through-holes 83 provided in the correction substrate 8 may be changed as appropriate, as long as it is two or more.

[0104] The first and second reference marks provided on the correction substrate 8 do not necessarily have to be the openings 831 and 832 of the through hole 83, and can be changed in various ways. For example, two marks that coincide in a plan view may be drawn on the first main surface 81 and the second main surface 82 of the correction substrate 8, and these two marks may be used as the first and second reference marks.

[0105] In the drawing device 1a, the correction information for the alignment mark drawing unit 51 and the correction information for the alignment mark drawing unit 51a do not necessarily need to be acquired using the same correction substrate 8, but may be acquired using separate correction substrates 8.

[0106] The substrate 9 described above is not necessarily limited to a printed circuit board. The drawing device 1,1a may, for example, perform position detection on semiconductor substrates, glass substrates for flat panel display devices such as liquid crystal displays and organic EL displays, glass substrates for photomasks, substrates for solar panels, etc.

[0107] The configurations in the above embodiments and each modified example may be combined as appropriate, as long as they do not contradict each other. [Explanation of Symbols]

[0108] 1,1a Drawing device 3. Imaging Unit 4 Pattern drawing section 8. Correction board 9 circuit boards Stage 21,21a 22,22a Stage movement mechanism 31 Alignment Camera 32a Camera movement mechanism 41 drawing head 42a Drawing head movement mechanism 51,51a Alignment mark drawing section 81 First main surface (of the correction substrate) 82 Second main surface (of the correction substrate) 83 Through hole 91 (of the substrate) First main surface 92 (Second main surface of the substrate) 93,94 Alignment Marks 831,832 (Opening of through hole) Steps S11-S14, S21-S23, S31-S37, S41-S46

Claims

1. A method for obtaining drawing position information in a drawing device, The drawing device is, A stage for holding the substrate, A stage movement mechanism that moves the aforementioned stage horizontally, An imaging unit for imaging the upper surface of the substrate held on the stage, A pattern drawing unit that draws a pattern by irradiating light onto the upper surface of the substrate held on the stage, An alignment mark drawing unit that irradiates light onto the lower surface of the substrate fixed to and held by the stage, and draws a plurality of alignment marks that serve as reference positions for drawing patterns on the lower surface, Equipped with, The method for obtaining drawing position information is as follows: a) A step of preparing a correction substrate in which two first reference marks are provided on the first main surface and two second reference marks are provided on the second main surface whose positions in a plan view coincide with the two first reference marks, b) A step of arranging the correction substrate, with the first main surface facing upward, so as to cover the alignment mark drawing section and holding it with the stage, c) A step of imaging the first main surface of the correction substrate with the imaging unit and obtaining the positions of the two first reference marks, d) A step of drawing the plurality of alignment marks on the second main surface of the correction substrate using the alignment mark drawing unit, e) a step after step d) in which the correction substrate with the second main surface facing upward is held by the stage, f) A step of imaging the second main surface of the correction substrate with the imaging unit to obtain the positions of the two second reference marks and the positions of the plurality of alignment marks, g) A step of acquiring drawing position information relating to the drawing positions of the plurality of alignment marks by the alignment mark drawing unit, based on the positions of the two first reference marks acquired in step c), and the positions of the two second reference marks and the plurality of alignment marks acquired in step f), A method for acquiring drawing position information, characterized by comprising the following features.

2. A method for obtaining drawing position information according to claim 1, A method for acquiring drawing position information, characterized in that the drawing position information acquired in step g) is correction information indicating the discrepancy between the design position of the plurality of alignment marks and the drawing position of the plurality of alignment marks by the alignment mark drawing unit.

3. A method for obtaining drawing position information according to claim 1, The two first reference marks are, respectively, openings on the first main surface of two through holes provided in the correction substrate. A method for acquiring drawing position information, characterized in that the two second reference marks are openings on the second main surface of the two through holes.

4. A method for obtaining drawing position information according to claim 1, The plurality of alignment marks are arranged along a predetermined alignment direction, A method for acquiring drawing position information, characterized in that the distance in the alignment direction between the two first reference marks is greater than or equal to the distance in the alignment direction between two alignment marks located at both ends of the alignment direction among the plurality of alignment marks.

5. A method for obtaining drawing position information according to claim 1, The drawing device is, Another stage that holds the substrate, Another stage moving mechanism that moves the aforementioned other stage horizontally, Another alignment mark drawing unit that is fixed to the other stage and holds the substrate and irradiates light onto the lower surface of the substrate, and draws a plurality of other alignment marks that serve as references for the drawing position when drawing a pattern on the lower surface, Furthermore, The pattern drawing unit, A drawing head that projects light downwards, A drawing head movement mechanism moves the drawing head between a first drawing position above the stage movement mechanism and a second drawing position above the other stage movement mechanism. Equipped with, The imaging unit is Alignment camera and The alignment camera is moved between a first imaging position above the stage movement mechanism and a second imaging position above the other stage movement mechanism by a camera movement mechanism, Equipped with, The method for obtaining drawing position information is as follows: h) A step of arranging the correction substrate, with the second main surface facing upward, so as to cover the other alignment mark drawing section, and holding it with the other stage, i) A step of imaging the second main surface of the correction substrate with the imaging unit and obtaining the positions of the two second reference marks, j) A step of drawing the other plurality of alignment marks on the first main surface of the correction substrate using the other alignment mark drawing unit, k) A step after step j) in which the correction substrate with the first main surface facing upward is held by the other stage, l) A step of imaging the first main surface of the correction substrate with the imaging unit to obtain the positions of the two first reference marks and the positions of the other plurality of alignment marks, m) A step of acquiring another drawing position information relating to the drawing position of the other plurality of alignment marks by the other alignment mark drawing unit, based on the positions of the two second reference marks acquired in step i) above, and the positions of the two first reference marks and the other plurality of alignment marks acquired in step l) above, A method for acquiring drawing position information, further characterized by comprising the following features.

6. A method for obtaining drawing position information according to claim 5, The appearance of the aforementioned multiple alignment marks is the same as that of each other. A method for acquiring drawing position information, characterized in that the appearance of the other plurality of alignment marks is the same as that of the plurality of alignment marks, and is different from the appearance of the plurality of alignment marks.

7. A drawing method for drawing patterns on a substrate, n) A step of holding the substrate with one main surface facing upward using the stage, o) The process of capturing a positioning mark on one of the main surfaces using the imaging unit, performing alignment processing on the substrate based on the output from the imaging unit, and drawing a pattern on the one of the main surfaces using the pattern drawing unit, p) A step of drawing the plurality of alignment marks on the other main surface of the substrate using the alignment mark drawing unit, q) A step of holding the substrate with the other main surface facing upward using the stage, r) The process of capturing the plurality of alignment marks on the other main surface with the imaging unit, performing alignment processing on the substrate based on the output from the imaging unit and the drawing position information acquired by the drawing position information acquisition method described in any one of claims 1 to 6, and drawing a pattern on the other main surface with the pattern drawing unit based on the plurality of alignment marks, A drawing method characterized by comprising the following:

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