TW202018422A - Mark position detecting apparatus, writing apparatus and mark position detecting method - Google Patents

Abstract

A writing apparatus includes a function as a mark position detecting apparatus detecting a position of a mark on a substrate held on a stage. The writing apparatus obtains a first image (83a) showing a first region on the substrate, the region including a position of a mark in design, and obtains a second image (83b) showing a second region a part of which overlaps on the first region while moving the stage. Further, the writing apparatus composes the first image (83a) and the second image (83b) to produce a composed image (85). The writing apparatus obtains a position of the mark on the basis of the composed image (85). This makes it possible to easily enlarge the field of vision without lowering resolution of the image capturing device, and to thereby reduce error of detecting a position of the mark on the substrate.

Description

Mark position detection device, drawing device and mark position detection method

[0001] The present invention relates to a technique for detecting the position of a mark on a substrate, and is preferably used in a drawing device for drawing a pattern on a substrate.

[0002] In the past, a drawing device that irradiates light on a substrate and directly draws a pattern on the substrate has been used in various scenes. This kind of drawing method is also called direct imaging. Before drawing, the position of the mark, which is offset from the design position, is obtained by reading the position of the mark called the alignment mark formed on the substrate with the imaging unit. Furthermore, the position of the substrate, the amount of expansion and contraction, the amount of distortion, and the like are obtained based on the offset, and drawing is performed while correcting the drawing data with reference to the information. With this, it is possible to draw with high accuracy in accordance with the positional deviation and deformation of the substrate. For example, the device disclosed in Japanese Patent Laid-Open No. 2015-64461 can be cited as such a drawing device. The direct imaging system is suitable for depicting substrates that are offset, deformed, and flexible. [0003] However, depending on the type and quality of the substrate, there may be a case where the position of the mark on the stage supporting the substrate is largely shifted. For example, in the case of a flexible substrate, since the cutting accuracy at the time of manufacturing the substrate is low and the handling accuracy is also low, the positional deviation of the mark when the substrate is placed on the table becomes large. In addition, in the case of a flexible substrate, the deformation of the substrate such as expansion and contraction and distortion is also a cause of the positional deviation of the mark. As a result, when photographing a mark, the frequency of the mark outside the shooting range becomes higher. Once the detection of the marked position fails, the manufacturing line is stopped and the productivity is greatly reduced. [0004] In order to be able to shoot even if the position of the mark is greatly shifted from the desired position, for example, it is necessary to move the imaging section away from the table and reduce the magnification of the optical system to expand the imaging range. In this case, the resolution of the image is lowered, and the detection accuracy of the position of the mark is lowered. Therefore, in order to maintain the resolution, it is necessary to increase the number of pixels of the imaging sensor, but in this case, the imaging section becomes expensive and the imaging section becomes physically large.

[0005] The purpose of the present invention is to reduce the detection error of the position of the mark by easily reducing the resolution of the photographing section and easily expanding the field of view. [0006] The present invention is a mark position detection device suitable for detecting the position of a mark on a substrate held by a table. A preferred form of the marker position detection device of the present invention is provided with: a table to hold the substrate; a photographing section to obtain an image of the marker formed on the substrate; a moving mechanism parallel to the substrate The direction of the main surface moves the table relative to the photographing section; the photographing control section acquires the first image and the second image by controlling the photographing section and the moving mechanism. The first image is Displaying a first area on the substrate, the first area including the design position of the mark, and the second image displaying a second area that only partially overlaps the first area; an image synthesis section, The first image is combined with the second image to generate a combined image; and the position acquisition unit obtains the position of the mark relative to the table based on the combined image. [0007] According to the present invention, it is possible to easily expand the field of view without reducing the resolution of the imaging section and reduce the detection error of the position of the mark on the substrate. [0008] Preferably, the first area and the second area respectively have long sides and short sides perpendicular to each other; the first area and the second area are arranged in a direction almost parallel to the short side. [0009] It is further preferred that the image synthesis unit utilizes the sum of the short sides of the first area and the second area when determining the relative position of the second image with respect to the first image The angle formed by the straight line connecting the center of the first area and the center of the second area. [0010] Preferably, the moving mechanism moves the table relatively linearly in the moving direction with respect to the photographing section; the photographing section acquires the aforesaid relative movement of the table relative to the photographing section The first image and the aforementioned second image. [0011] Preferably, the moving mechanism moves the table relatively linearly in the moving direction with respect to the imaging unit; the imaging unit obtains a picture of an odd number of plural regions arranged in the moving direction For example, only a part of each of the plurality of regions overlaps the adjacent region; the first region is the central region among the plurality of regions; and the second region is a region adjacent to the first region. [0012] Preferably, the pixel value of a portion where the first image overlaps with another image in the composite image is the pixel value of the first image. [0013] In a preferred embodiment, the mark position detection device is further provided with: another photographing unit that acquires an image of another mark formed on the substrate; the photographing control unit controls the other The photography unit and the moving mechanism acquire another first image and another second image. The other first image displays another first area on the substrate, and the other first area includes the The design position of the aforementioned another mark, the aforementioned another second image shows another second area where only a part overlaps with the aforementioned another first area; the aforementioned image synthesizing section compares the aforementioned another first image The image is synthesized with the aforementioned another second image to generate another synthesized image; the size of the aforementioned synthesized image is the same as the size of the aforementioned another synthesized image. [0014] Preferably, the aforementioned substrate is flexible. [0015] The present invention is also suitable for a drawing device for drawing a pattern on a substrate. The drawing device is provided with: the above-mentioned mark position detecting device, which detects the positions of a plurality of marks formed on the substrate; the correction part, which corrects the drawing data according to the positions of the plurality of marks; The substrate is irradiated with modulated light; and a drawing control unit controls the moving mechanism and the drawing head, thereby drawing on the substrate based on the corrected drawing data. [0016] The present invention is also suitable for a mark position detection method for detecting the position of a mark on a substrate held by a table. The mark position detection method includes: step (a), which obtains a first image that displays a first area including a design position of the mark on the substrate held by the table; and step (b) ), a second image is obtained, the second image shows a second area that only partially overlaps the first area; step (c), the first image is combined with the second image Generating a composite image; and step (d), the position of the mark relative to the table is obtained from the composite image. [0017] The above-mentioned objectives and other objectives, features, aspects, and advantages can be understood by referring to the attached drawings and by the following detailed description of the present invention.

[0019] FIG. 1 is a block diagram showing the structure of a rendering system 100 according to an embodiment of the present invention. The drawing system 100 is a system for irradiating light to a photosensitive material on a substrate such as a printed wiring board and drawing a pattern of wiring or the like on the photosensitive material. Preferably, the substrate is a flexible printed circuit board. As the substrate, various other substrates may be used, and it may be a rigid substrate or a substrate other than wiring used for circuits. [0020] The rendering system 100 is provided with a computer 101 and a rendering device 1. The drawing device 1 includes a function as a mark position detection device for detecting the position of the mark on the substrate. The computer 101 is used to generate design data that displays the overall pattern that should be drawn on the substrate. The design data is, for example, vector data showing the overall pattern. The drawing device 1 includes a computer 21 and a device body 10. The computer 21 is responsible for the overall control of the device body 10. The computer 21 also generates drawing data used in the design data generating device body 10. The computer 101, the computer 21, and the device body 10 are communicably connected to each other. [0021] FIG. 2 is a perspective view of the display device body 10. In FIG. 2, three directions orthogonal to each other are shown as arrows in the X direction, Y direction, and Z direction (the same is true in other drawings). In the example of FIG. 2, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction. Depending on the design of the drawing device 1, the Z direction may be a direction inclined to the vertical direction or a horizontal direction. [0022] The apparatus body 10 is provided with a plurality of drawing heads 31, a table 41, a table lifting mechanism 42, a table moving mechanism 43, and a photographing unit 5. The table 41 holds the substrate 9 below the drawing head 31 ((-Z) side). The plurality of drawing heads 31 are arranged in the X direction (hereinafter, also referred to as "width direction"). In each drawing head 31, laser light is emitted from the light source toward the light modulation section, and the light is modulated by the light modulation section. The modulated (spatially modulated) light system irradiates the main surface 91 in the (+Z) direction in the substrate 9 on the table 41. In the present embodiment, a DMD (digital mirror device) in which a plurality of micro mirrors are arranged two-dimensionally is used as the optical modulation section of each drawing head 31. The optical modulation section may also be a modulator in which a plurality of optical modulation elements are arranged one-dimensionally. [0023] The table lifting mechanism 42 moves the table 41 in the Z direction. The table moving mechanism 43 moves the table 41 together with the table elevating mechanism 42 in the Y direction (hereinafter, also referred to as "moving direction"). The table moving mechanism 43 is, for example, a mechanism for linearly moving the table 41 along the guide rail, and uses, for example, a linear servo motor (linear servo motor) as a driving source. With this, the table 41 is moved with high accuracy. It is also possible to use a ball screw mounting motor as the driving source of the table moving mechanism 43. In the drawing device 1, the table lifting mechanism 42 may be omitted, or a rotating mechanism may be provided that rotates the table 41 with an axis parallel to the Z direction as the center. [0024] The photographing unit 5 is arranged on the (-Y) side of the plurality of drawing heads 31. The photography unit 5 includes a plurality of photography units 51. The plural imaging units 51 are arranged at intervals in the width direction. Each photographing unit 51 is the substrate 9 on the photographing stage 41 and acquires image data. The imaging unit 51 acquires an image of a so-called alignment mark, which is a mark formed on the substrate 9. The photographing unit 51 is a so-called digital still camera including a two-dimensional image sensor and a photographing optical system. [0025] On the table 41, a contact portion 411 that contacts the edge of the substrate 9 is provided. When the substrate 9 is placed on the table 41, the position and direction of the substrate 9 on the table 41 can be determined by the edge of the substrate 9 contacting the contact portion 411. In this embodiment, the contact portion 411 is three pins. The contact portion 411 is not limited to a pin, and may be, for example, a portion extending in the X direction and Y direction and protruding upward. The substrate 9 is fixed on the table 41 by suction. The substrate 9 may be fixed to the table 41 by other methods. [0026] In the drawing of the pattern by the drawing head 31, the table moving mechanism 43 continuously moves the table 41 in the moving direction, and the position on the substrate 9 irradiated with the light from each drawing head 31 is opposed The substrate 9 is scanned in the moving direction. In addition, in synchronization with the movement of the table 41, the DMD of the drawing head 31 is controlled. With this, the pattern of each drawing head 31 is drawn on the belt area extending in the moving direction on the main surface 91. [0027] In this embodiment, the pattern is drawn in the entire drawing area of the substrate 9 by one continuous movement of the table 41 in the moving direction (so-called one pass drawing). In the drawing device 1, the entire pattern in the drawing area can also be drawn by repeating the continuous movement of the table 41 in the moving direction and the intermittent movement in the width direction perpendicular to the moving direction (so-called multiple passes) Multipass drawing). [0028] FIG. 3 is a side view of a part of the display device body 10. FIG. 3 is a view of the device body 10 viewed in the (-X) direction. Each imaging unit 51 can be moved in the X direction by the imaging unit moving mechanism 52. The photographing unit moving mechanism 52 is, for example, a mechanism for driving a ball screw with a motor and a mechanism for guiding the ball screw in the X direction. A linear servo motor can also be used as the driving source of the moving mechanism 52 of the photographing unit. The photography unit 51 includes an illumination unit 53. The lighting unit 53 is a link lighting device. As the illumination unit 53, a device for irradiating illumination light onto the substrate 9 via the imaging optical system may be used. A lighting device 53 may be combined with a link lighting device and a device for lighting through a photographic optical system. [0029] A scale 44 is provided at the end of the (+Y) side of the work table 41. As long as the scale 44 is fixed to the table 41, it may be installed at another position. The scale 44 is long in the X direction and exists in the entire drawable range in the X direction. The scale 44 is a transparent plate having a plurality of cross patterns arranged in the X direction on the plate. Other shapes can also be used as the pattern of the scale 44. [0030] Below the scale 44, a lower photographing section 61 is arranged. The lower imaging unit 61 can be moved in the X direction by the lower imaging unit moving mechanism 62. The lower camera moving mechanism 62 is, for example, a mechanism for driving a ball screw with a motor and a mechanism for guiding the ball screw in the X direction. A linear servo motor can also be used as the driving source of the moving mechanism 62 of the lower imaging unit. In a state where a predetermined pattern of light is emitted from one drawing head 31 to the scale 44, the lower photographing unit 61 acquires an image of the scale 44 and obtains the position between the drawing head 31 and the scale 44 by calculating the image by calculation relationship. Since the scale 44 is fixed to the table 41, the positional relationship between the drawing head 31 and the table 41 is also obtained. [0031] Each drawing head 31 is movable in the X direction by a head moving mechanism 32. The head moving mechanism 32 combines, for example, a mechanism for driving the ball screw with a motor and a mechanism for guiding the ball screw in the X direction. A linear servo motor can also be used as the driving source of the head moving mechanism 32. The acquisition of the positional relationship between each drawing head 31 and the table 41 is performed every time the drawing head 31 is rearranged in accordance with the pattern drawn by the substrate 9. The positional relationship between all the drawing heads 31 and the table 41 may be obtained by moving one lower imaging unit 61 in the X direction, or a plurality of lower imaging units 61 may be provided and a portion of the rendering may be acquired by one lower imaging unit 61 The relationship between the head 31 and the table 41. [0032] In addition, by changing the position of the table 41 and allowing the photographing unit 51 to photograph the scale 44, the positional relationship between the photographing unit 51 and the table 41 can also be obtained. The positional relationship between the photographing unit 51 and the scale 44 may be acquired only once before drawing, but it may be performed every time the table 41 moves during photographing of a marker described later. [0033] FIG. 4 is a block diagram showing the functional configuration of the computer 21 together with the peripheral configuration. The functional configuration of the computer 21 is realized by the computer 21 executing a program. That is, through the computer 21's CPU (Central Processing Unit; central processing unit), ROM (Read Only Memory; read only memory), RAM (Random Access Memory; random access memory), fixed disk, interface, etc. The program operates to realize each functional structure. Each functional configuration can also be realized by a dedicated electronic circuit or a dedicated electronic circuit and program execution. The computer 21 can be a plurality of computers, or can be realized by a combination of a dedicated electronic circuit and a plurality of computers. [0034] The computer 21 includes an imaging control unit 211, an image synthesis unit 212, a position acquisition unit 213, a correction unit 214, a rendering control unit 215, and a memory unit 216. The memory portion 216 is mainly realized by a fixed disk device or a memory element of the computer 21. The photographing control section 211 controls the stage moving mechanism 43 and controls the photographing by the photographing section 51 in accordance with the signal from the stage moving mechanism 43. The image synthesis unit 212 synthesizes a plurality of images acquired by the imaging unit 51. The position obtaining unit 213 obtains the position of the mark relative to the table 41 based on the mark image (hereinafter, referred to as “mark image”) appearing in the composite image. The memory section 216 is a memory drawing data 8. The correction unit 214 obtains the position and deformation of the substrate 9 based on the position of the mark, and corrects the drawing data 8. The drawing control unit 215 controls the table moving mechanism 43 and the drawing head 31 to perform drawing on the substrate 9 based on the corrected drawing data 8. [0035] In the following description, the acquisition of an image refers to the acquisition of image data, and the processing of an image refers to the processing of image data. [0036] FIG. 5 is a diagram showing a flow of drawing operations of the device 1. As described above, in the drawing device 1, after detecting the position of the mark on the substrate 9 (steps S11 to S15), the drawing data 8 is corrected according to the position of the mark and the position and deformation of the substrate 9 (step S16 ), draw a pattern on the substrate 9 according to the corrected drawing data (step S17). To be precise, the “mark position” refers to the relative position of the mark with respect to the reference position set based on the table 41. The "position relative to the table 41" refers to a relative position with respect to the reference position set at the table 41. 6 is a plan view showing an example of the arrangement of marks 92 on the substrate 9. The mark 92 is, for example, a pattern of a tiny hole formed in the substrate 9 or a copper foil formed on the substrate 9. Various patterns such as crosses and circles can be used as patterns for copper foil. In the case of the example of FIG. 9, nine marks 92 are arranged in three rows and three columns in the X direction and the Y direction. The position of the mark 92 in the X direction corresponds to the position of the imaging unit 51 in the X direction. Of course, the position and number of marks 92 can be variously changed. [0038] The position of the photographing unit 51 relative to the table 41 is obtained in advance using a scale 44. The position of the imaging unit 51 with respect to the table 41 includes the rotational position of the imaging unit 51 with respect to the table 41, that is, the rotation amount of the imaging unit 51 centered on the axis toward the Z direction. The amount of rotation is a minute amount of error when the imaging unit 51 is installed in the device. [0039] If the substrate 9 is arranged on the table 41 such that the edge of the substrate 9 contacts the contact portion 411 of the table 41, the positions of the marks 92 in the X direction are the same as those of any imaging unit 51 in the X direction The location is probably the same. In this state, the substrate 9 starts the movement of the table 41 so as to pass under the imaging unit 51 (step S11). The moving direction of the table 41 may be the (+Y) direction or the (-Y) direction. When each mark 92 passes under any of the imaging units 51, the imaging unit 51 is controlled by the imaging control unit 211 to acquire a plurality of images (step S12). After that, the moving table 41 is stopped (step S13). [0040] FIG. 7 is a diagram of the regions 93a and 93b on the substrate 9 that is associated with one mark 92 and becomes a photographing target in step S12. The areas 93a and 93b are collectively referred to as "area 93". In the example of FIG. 7, the three regions 93b, 93a, and 93b are arranged in the Y direction with respect to one mark 92 in sequence. FIG. 7 shows the position of the design mark 92 in the case where the substrate 9 has no positional deviation and no deformation such as expansion and contraction or distortion. [0041] In the following description, the area 93a including the position of the design mark 92 is referred to as a "first area", and the area 93b where only a portion overlaps the first area 93a is referred to as a "second area". In addition, the image displaying the first area 93a is referred to as a "first image", and the image displaying the second area 93b is referred to as a "second image". The position of the design mark 92 is the center of the first area 93a. The two second regions 93b are in the Y direction before and after the first region 93a and only a part of the region overlaps the first region 93a. [0042] Each area 93 is a rectangle having long and short sides perpendicular to each other. The first region 93a and the second region 93b are arranged in a direction almost parallel to the short side. The short side system is almost parallel to the Y direction. The expression "almost parallel to the Y direction" also includes the case parallel to the Y direction. The size of the region 93 is, for example, about 14 mm on the long side and about 7 mm on the short side. The distance between the centers of adjacent regions 93 is about 4 mm. Although the area 93 is deliberately depicted as being inclined in the Y direction in FIG. 7, the inclination of the area 93, that is, the rotation amount of the area 93 is actually the degree of error when the imaging unit 51 is installed in the device as described above. [0043] The photographing control unit 211 controls the photographing unit 51 and the table moving mechanism 43 so that the photographing by the photographing unit 51 can be performed without stopping the table 41 during the movement of the table 41. In order to realize photography while the table 41 is moving, the illumination unit 53 emits light momentarily when the table 41 passes a predetermined position, and the light is used for instant photography. When the lighting unit 53 emits light three times, the second image, the first image, and the second image are sequentially acquired from the second area 93b, the first area 93a, and the second area 93b, respectively. By acquiring a plurality of images during the relative movement of the table 41 relative to the photographing unit 51, the plurality of images can be quickly acquired. [0044] FIG. 8 is a diagram for explaining the processing performed by the image synthesizing unit 212. The image synthesis unit 212 synthesizes one first image 83a and two second images 83b to generate a synthesized image (step S14). In FIG. 8, directions perpendicular to each other in the two-dimensional space for synthesizing images are displayed as the x direction and the y direction. The x direction and the y direction are the directions in which pixels are arranged. The x direction corresponds to the longitudinal direction of the first image 83a and the second image 83b. The y direction corresponds to the short side direction of the first image 83a and the second image 83b. [0045] In the case where the first image 83a and the second image 83b are arranged in the xy space, the Y direction in FIG. 7 corresponding to these images becomes the direction in which the area 93 is inclined up to the inclined angle θ. Here, as shown in FIG. 8, the Y direction rotates clockwise with respect to the y direction to a direction of (−θ). In addition, let the distance in the xy space corresponding to the distance D (refer to FIG. 7) between the center of the first region 93a and the center of the second region 93b be d. In addition, in the xy space of FIG. 7, the y direction corresponds to the direction of the short sides of the first region 93 a and the second region 93 b, and the Y direction corresponds to the moving direction, that is, the center of the first region 93 a and the second region 93 b A straight line connecting the center of. In this way, if the angle θ is expressed with the area 93 as a reference, the angle θ is the angle formed by the straight line between the short side of the area 93 and the center of the area. [0046] The image synthesis unit 212 arranges the first image 83a and the second image 83b in the xy space in order to maintain the relative positional relationship between the first region 93a and the second region 93b, so that (+y ) Side of the center of the second image 83b relative to the center of the first image 83a is located on the (+y) side up to d·cosθ and relative to the center of the first image 83a on the (-x) side up to d sinθ. Similarly, the center of the (-y) side second image 83b is located on the (-y) side relative to the center of the first image 83a up to d·cosθ, and the center of the first image 83a is located on the (+ x) The side reaches d·sinθ. Since the position of the table 41 can be accurately acquired, the distance D and the distance d can be accurately acquired. When the relative position of the second image 83b with respect to the first image 83a is obtained, the image synthesizing unit 212 uses not only the distance d but also the angle θ, so that it can be synthesized with high accuracy. As shown in FIG. 9, the mark image 82 is designed to appear in the center of the first image 83a. In this way, by overlapping the first image 83a and the second image 83b as described above, even if it is assumed that the mark image 82 exceeds the mark image 82 from the first image 83a in the (±y) direction, it will still appear in the second Image 83b. [0048] For example, even if the cutting position is shifted or tilted due to low cutting accuracy at the time of manufacturing the substrate 9, or due to deformation of the substrate 9, such as expansion and contraction of the substrate 9, the image 82a is marked as shown by the element symbol 82a In the case where the whole or a part of the image is not displayed on the first image 83a, as long as the mark image 82a appears in the second image 83b, the position acquisition unit 213 can still detect the position of the mark image 82 in the composite image 85. In addition, actually, the synthesized image 85 is trimmed by the range indicated by the broken line in FIG. 9 before the mark detection processing is performed by the position acquisition unit 213. Since the position of the photographing unit 51 relative to the table 41 is obtained in advance, the position obtaining unit 213 can detect the position of the actual mark 92 relative to the table 41 based on the position of the mark image 82 in the composite image 85 (step S15) . [0049] As described above, by using the synthesized image 85 in the rendering device 1, the field of view can be easily expanded without reducing the resolution of the photographing unit 51, and the detection error of the position of the mark 92 can be reduced. In addition, since the imaging unit 51 is arranged so that the short side of the area 93 becomes almost parallel to the Y direction, the width of the composite image 85 in the x direction is ensured, and the composite image 85 can be easily approached into a large square. As a result, when the mark 92 deviates from the design position, the mark 92 can be easily received in the visual field. [0050] Here, as shown in FIG. 9, the image synthesizing unit 212 preferentially synthesizes the first image 83a in a region where the first image 83a and the second image 83b overlap. That is, the pixel value of the portion of the composite image 85 where the first image 83a and the second image 83b overlap becomes the pixel value of the first image 83a. As a process of preferentially synthesizing the first image 83a, the first image 83a may be overwritten after the second image 83b is written into the memory space, or each pixel in the memory space may be selectively written one by one image. [0051] Since the mark image 82 is designed to appear in the center of the first image 83a, the probability that the mark image 82 appears in the first image 83a is actually higher than that in the second image 83b. Therefore, by preferentially using the first image 83a over the second image 83b, the probability that the marker image 82 and the synthesized boundary in the synthesized image 85 overlap may be reduced. As a result, the mark image 82 can be made to appear clearly in the composite image 85, and the decrease in the detection accuracy of the position of the mark 92 can be suppressed. [0052] In the examples of FIGS. 7 to 9, although three images are acquired during the relative movement of the table 41 relative to the photographing unit 51, the number of images is not limited to three. Preferably, the imaging unit 51 acquires images of an odd number of plural regions arranged in the moving direction, and each of the plural regions only partially overlaps the adjacent regions. At this time, the design position of the mark image 82 is set at the center of the central image corresponding to the first image 83a. In addition, as in the case of FIG. 8, in the composite image, the pixel value of the portion where the center image overlaps with another adjacent image is the pixel value of the center image. Thereby, the possibility that the mark image 82 crosses two images can be reduced. Even in the case where a plurality of images are acquired for one mark 92, since the images are acquired during the movement of the substrate 9, the time required to acquire the images is the same as the case where only one image is acquired. The area where the adjacent regions 93 overlap is preferably 1/10 or more and 1/3 or less of the area of the region 93. [0053] The drawing device 1 as shown in FIG. 2 is provided with three photographing sections 51, and as shown in FIG. 6, when nine marks 92 are arranged on the substrate 9 in three rows and three columns, the mechanism is moved by the table. 43 While the table 41 is moved once in the Y direction, each imaging unit 51 acquires the mark image 82 three times. In the acquisition of each mark image, a plurality of photographs are performed as described above, and images are synthesized. Thereby, nine mark images 82 can be acquired at high speed. [0054] At this time, under the control of each imaging unit 51 and the table moving mechanism 43 by the imaging control unit 211, each imaging unit 51 similarly acquires an image. For example, when one first image 83a and two second images 83b shown in FIG. 8 are acquired by one imaging unit 51, one first image 83a is also acquired at the other imaging unit 51 And two second images 83b. Then, after the synthesis by the image synthesis unit 212, the synthesized image 85 is trimmed to the same size. Thereby, nine composite images 85 of the same size corresponding to the nine marks 92 are obtained. By setting the plurality of composite images 85 to the same size regardless of the type and size of the mark 92, most of the detection processing of the position of the mark 92 can be made common, and the production or hardware of the detection program can be changed It's easy. [0055] The drawing device 1 may have various changes. [0056] The second image 83b may also be one. In this case, the number of images acquired for one mark 92 is two. Preferably, the number of images acquired for one mark 92 is 3 or more. Preferably, the number of acquired images is an odd number of 3 or more, but it may be an even number. [0057] When acquiring an image, the movement of the table 41 may also be stopped. That is, the process of acquiring the first image 83a and the process of acquiring the second image 83b do not need to be performed continuously. In the case where the table 41 is stopped during shooting, an inexpensive shooting section may be used as the shooting section 51. The first area 93a and the second area 93b may be arranged in the X direction, that is, a direction perpendicular to the moving direction of the table 41. In this case, a moving mechanism that moves the imaging unit 51 or the table 41 in the X direction with high accuracy may be provided. Furthermore, four second regions 93b may be set at the positions of front, back, left, and right of the first region 93a, or eight second regions 93b may be set at positions of the first region 93a near eight. [0058] In the case where the pixels of the image sensor of the photographing section 51 are correctly arranged in the XY direction, the angle θ formed between the Y direction and the y direction when synthesizing the image becomes 0, and there is no need to consider Angle θ. When compositing images, the first image 83a may not be prioritized, but may be synthesized by simply overwriting in the order of photography. [0059] The mark 92 need not be a dedicated alignment mark. For example, the imaging unit 51 can also use the through hole or the characteristic pattern formed in the substrate 9 as the mark 92. [0060] The table 41 does not need to determine the position of the substrate 9 by the contact portion 411. For example, the table 41 may hold the end of the substrate 9. Alternatively, the substrate 9 may be simply placed. [0061] A moving mechanism for moving the imaging unit 51 linearly relative to the table 41 may be provided in a direction parallel to the main surface of the substrate 9 to replace the table moving mechanism 43. It suffices that the table 41 moves relative to the imaging unit 51. [0062] The configuration of the mark 92 may be changed as appropriate. Preferably, the imaging unit 51 is arranged at each position of the mark 92 in the X direction. Of course, the number of positions of the mark 92 in the X direction may be larger than the number of the imaging unit 51. In this case, after the movement of the table 41 in the Y direction and the shooting are completed, the photographing unit 51 moves in the X direction, and the table 41 is moved again in the Y direction while shooting. [0063] The processing system for detecting the position of the mark image 82 from the composite image 85 may be performed for each mark 92 one by one, or may be processed in parallel. [0064] The light emitted from the drawing head 31 may also be a beam modulated by ON/OFF (on/off). [0065] The drawing device 1 may also be provided with a moving mechanism for moving the drawing head 31 in the moving direction. That is, the drawing device 1 is provided with a moving mechanism that moves the table 41 relative to the drawing head 31 and continuously moves in the moving direction. [0066] In addition to the printed wiring substrate, the patterned substrate 9 may be a semiconductor substrate, a glass substrate, or the like. Although the substrate 9 is preferably a flexible substrate, it is not limited to a printed circuit board. [0067] The configuration in the above-mentioned embodiments and the modified examples can be combined as appropriate without contradicting each other. [0068] Although the present invention is described and described in detail, the above description is only an example and not a limitation. As such, there can be multiple variations and appearances without departing from the scope of the present invention.

[0069] 1: Drawing device (mark position detection device) 5: Photography unit 8: Describe the data 9: substrate 10: Device body 21: Computer 31: Paint head 32: head moving mechanism 41: Workbench 42: table lifting mechanism 43: Worktable moving mechanism 44: Ruler 51: Photography Department 52: Mobile Department of Photography Department 53: Lighting Department 61: Lower Photography Department 62: Moving mechanism of lower photography department 82, 82a: mark like 83a: first image 83b: second image 85: Composite image 91: Main surface 92: Mark 93a: first area 93b: Second area 100: drawing system 101: Computer 211: Photography Control Department 212: Image synthesis department 213: Position acquisition department 214: Correction Department 215: Drawing Control Department 216: Memory Department Workbench 411 D, d: distance θ: angle

[0018] FIG. 1 is a block diagram showing the composition of the drawing system. 2 is a perspective view of the display device body. 3 is a side view showing a part of the device body. FIG. 4 is a block diagram showing the functional configuration of a computer and the peripheral configuration. FIG. 5 is a diagram showing the flow of the operation of the drawing device. 6 is a plan view showing an example of the arrangement of marks on a substrate. 7 is a diagram illustrating an area on a substrate to be photographed. FIG. 8 is a diagram for explaining the processing of the image synthesis unit. FIG. 9 is a diagram for explaining the processing of the image synthesis unit.

82, 82a: mark like

83a: first image

83b: second image

85: Composite image

Claims (10)

A mark position detection device is used to detect the position of a mark on a substrate held by a worktable, and is provided with: The aforementioned workbench holds the aforementioned substrate; The photography department acquires images of the marks formed on the substrate; The moving mechanism moves the table relative to the imaging unit in a direction parallel to the main surface of the substrate; The photography control unit acquires a first image and a second image by controlling the photography unit and the movement mechanism, the first image displays a first area on the substrate, and the first area includes the In terms of the design position of the mark, the aforementioned second image shows a second area where only a portion overlaps with the aforementioned first area; An image synthesis unit that synthesizes the first image and the second image to generate a synthesized image; and The position acquisition unit obtains the position of the mark relative to the table based on the synthesized image. The mark position detection device according to claim 1, wherein the first area and the second area have long sides and short sides perpendicular to each other, respectively; The first area and the second area are arranged in a direction almost parallel to the short side. The marker position detection device according to claim 2, wherein the image synthesis unit uses the first area and the second area when determining the relative position of the second image relative to the first image The angle formed by the straight line connecting the short side of the first area and the center of the first area and the center of the second area. The mark position detection device according to claim 1, wherein the moving mechanism moves the table relatively linearly in the moving direction with respect to the imaging unit; The imaging unit acquires the first image and the second image during the relative movement of the table relative to the imaging unit. The mark position detection device according to claim 1, wherein the moving mechanism moves the table relatively linearly in the moving direction with respect to the imaging unit; The photographing unit acquires images of an odd number of plural regions arranged in the moving direction, and each of the plural regions only overlaps with adjacent regions; The first area is the central area of the plurality of areas; The second area is an area adjacent to the first area. The marker position detection device according to claim 1, wherein the pixel value of a portion where the first image overlaps another image in the composite image is the pixel value of the first image. The mark position detection device according to claim 1, further comprising: another photographing section that acquires an image of another mark formed on the substrate; The photography control unit obtains another first image and another second image by controlling the other photography unit and the moving mechanism, and the other first image displays another first image on the substrate Area, the other first area includes the design position of the another mark, and the other second image shows another second area that only partially overlaps the other first area; The image synthesis unit synthesizes the other first image and the other second image to generate another synthesized image; The size of the aforementioned composite image is the same as the size of the aforementioned another composite image. The mark position detection device according to claim 1, wherein the substrate has flexibility. A drawing device is used to draw a pattern on a substrate, and is provided with: The mark position detection device described in any one of claims 1 to 8 detects the positions of a plurality of marks formed on the substrate; The correction section corrects the drawing data according to the positions of the aforementioned plural marks; A drawing head, which irradiates the modulated light on the substrate on the working table; and The drawing control unit controls the moving mechanism and the drawing head to draw on the substrate based on the corrected drawing data. A mark position detection method is used to detect the position of a mark on a substrate held by a worktable, and has: In step (a), a first image is obtained, and the first image shows a first area including the design position of the mark on the substrate held by the table; In step (b), a second image is obtained, and the second image displays a second area where only a portion overlaps with the first area; Step (c) is to synthesize the first image and the second image to generate a composite image; and Step (d) is to obtain the position of the mark relative to the table based on the synthesized image.

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