Pattern drawing apparatus and pattern drawing method

Abstract

To provide a pattern drawing apparatus in which an influence of an error of a moving amount of an irradiation region group in a sub-scanning direction which is given to a pattern to be drawn is made smaller.SOLUTION: In a pattern drawing apparatus, light irradiation is performed to a preceding stripe region 831 on a substrate by moving a preceding irradiation region group 821 in parallel with a main scanning direction. By moving a following irradiation region group 822 in parallel with the main scanning direction, light irradiation is performed to a following stripe region 832 which is adjacent to the preceding stripe region 831 and partially overlaps in an overlapped region 833. A portion passing through the overlapped region 833 of the contour of the preceding irradiation region group 821 is a first stairway-shaped part 823 where a linear part extending in the main scanning direction and a step part extending in a direction crossing to the main scanning direction are repeated, and a portion passing through the overlapped region 833 of the contour of the following irradiation region group 822 is a second stairway-shaped part 824 which compensates the first stairway-shaped part 823.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a technique for drawing a pattern on an object by irradiating it with light. [Background technology]

[0002] Conventionally, techniques have been used to draw fine patterns on photosensitive materials by scanning the photosensitive material with spatially modulated light. For example, in Patent Document 1, a pattern is drawn on the photosensitive material by main-scanning an array of irradiation areas on the photosensitive material, to which light from a group of micromirrors in a DMD (Digital Micromirror Device) is directed, while tilting the array with respect to the main-scanning direction. Each time the irradiation area group is main-scanned, the irradiation area group is intermittently moved in the sub-scanning direction, so that the area drawn in the preceding main scan and the area drawn in the subsequent main scan partially overlap. Furthermore, Figure 28 of Patent Document 1 discloses a configuration in which both ends of the irradiation area group in the sub-scanning direction are shaped such that a step is provided on a straight line parallel to the main-scanning direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-70506 Summary of the Invention [Problem to be solved by the invention]

[0004] However, slight errors may occur in the amount of movement of the irradiation area group in the sub-scanning direction. That is, when the irradiation area group completes one main scan and moves in the sub-scanning direction to perform the next main scan, the irradiation area group may deviate slightly from its ideal position. In this case, in the example shown in FIG. 28 of Patent Document 1, if the preceding irradiation area group and the succeeding irradiation area group overlap more than necessary, an area with a significant increase in light intensity occurs. If the preceding irradiation area group and the succeeding irradiation area group do not overlap sufficiently, an area with a significant decrease in light intensity occurs. In recent years, as the resolution of drawing patterns has increased, increases and decreases in light intensity, which were not previously a problem, are no longer acceptable.

[0005] On the other hand, it is desirable that both ends of the irradiation area group in the sub-scanning direction include as many edge portions parallel to the main scanning direction as possible for various technical reasons such as data processing for positional deviation correction.

[0006] The present invention has been made in view of the above-mentioned problems, and aims to reduce the influence of errors in the amount of movement of irradiation area groups in the sub-scanning direction when a pattern is written. [Means for solving the problem]

[0007] A first aspect of the present invention is a pattern drawing device that draws a pattern on an object by irradiating it with light, comprising: a light irradiation unit that irradiates light onto the object; an irradiation area moving mechanism that moves, on the object, an irradiation area group that is irradiated with light from the light irradiation unit; and a control unit that controls the movement of the irradiation area group and the irradiation of light onto each irradiation area of ​​the irradiation area group, and performs drawing on the object by irradiating each position on the object with light while passing a plurality of irradiation areas through the plurality of irradiation areas. Under the control of the control unit, the light irradiation onto the preceding irradiation area group from the light irradiation unit is controlled and the preceding irradiation area group is moved parallel to the main scanning direction, so that the preceding stripe area on the object is irradiated with light; and the light irradiation onto the subsequent irradiation area group from the light irradiation unit is controlled and the subsequent irradiation area group is moved parallel to the main scanning direction, so that the preceding stripe area on the object is irradiated with light. Light is irradiated to a subsequent stripe region that is adjacent to a row stripe region and partially overlaps with it in an overlapping region, and the previous irradiation region group or the subsequent irradiation region group passes continuously at each position of the non-overlapping region in the previous stripe region and the subsequent stripe region at a constant time, and the portion of the outline of the previous irradiation region group that passes through the overlapping region is a first staircase shape that repeats straight line portions extending in the main scanning direction and step portions extending in a direction intersecting the main scanning direction, and the portion of the outline of the subsequent irradiation region group that passes through the overlapping region is a second staircase shape that complements the first staircase shape, and both straight line portions included in the first staircase shape and the second staircase shape are 1% to 20% of the cutting length when the previous irradiation region group and the subsequent irradiation region group are cut in the non-overlapping region by a straight line parallel to the main scanning direction.

[0008] A second aspect of the present invention is a pattern drawing device of the first aspect, wherein the light irradiation unit has a spatial light modulator in which a plurality of light modulation elements are arranged two-dimensionally within a rectangular area, and a group of effective light modulation elements among the plurality of light modulation elements corresponds to the group of irradiation areas on the object.

[0009] A third aspect of the present invention is the pattern writing device of the second aspect, wherein the plurality of light modulation elements are a plurality of micromirrors whose attitudes can be changed individually.

[0010] A fourth aspect of the present invention is a pattern drawing device according to the second or third aspect, wherein a plurality of regions on the object corresponding to the plurality of light modulation elements are arranged in a rectangular shape in row and column directions that are perpendicular to each other, the column direction is inclined with respect to the main scanning direction, and the direction in which the first staircase shape and the second staircase shape extend is more along the main scanning direction than the column direction.

[0011] A fifth aspect of the present invention is the pattern writing device of the first aspect (which may be any one of the first to fourth aspects), wherein the width of the overlapping region is 0.1% to 20% of the width of the non-overlapping region.

[0012] A sixth aspect of the present invention is a pattern drawing method for drawing a pattern on an object by moving an irradiation region group to be irradiated with light on the object while controlling the irradiation of light onto each irradiation region of the irradiation region group, and irradiating each position on the object with light while passing a plurality of irradiation regions through the plurality of irradiation regions, the method comprising the steps of: controlling the irradiation of light onto the preceding irradiation region group while moving the preceding irradiation region group parallel to a main scanning direction, thereby irradiating light onto a preceding stripe region on the object; and controlling the irradiation of light onto a subsequent irradiation region group while moving the subsequent irradiation region group parallel to the main scanning direction, thereby irradiating light onto a subsequent stripe region adjacent to the preceding stripe region and partially overlapping with the preceding stripe region in an overlapping region. At each position of the non-overlapping region in the preceding stripe region and the following stripe region, the preceding irradiation region group or the following irradiation region group passes continuously at a constant time, the portion of the outline of the preceding irradiation region group that passes through the overlapping region is a first staircase shape that repeats straight line portions extending in the main scanning direction and step portions extending in a direction intersecting the main scanning direction, the portion of the outline of the following irradiation region group that passes through the overlapping region is a second staircase shape that complements the first staircase shape, and both straight line portions included in the first staircase shape and the second staircase shape are 1% to 20% of the cutting length when the preceding irradiation region group and the following irradiation region group are cut in the non-overlapping region by a straight line parallel to the main scanning direction. [Effects of the Invention]

[0013] According to the present invention, it is possible to minimize the influence of an error in the amount of movement of the irradiation region group in the sub-scanning direction on the pattern to be written. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view showing a configuration of a pattern writing device. [Figure 2] FIG. 2 is a perspective view showing a drawing head. [Figure 3] FIG. 1 is a diagram showing a DMD. [Figure 4] 1A and 1B are diagrams for explaining drawing of patterns on a substrate by a plurality of drawing heads. [Figure 5] FIG. 10 is a diagram showing the flow of operations of the pattern writing device. [Figure 6] FIG. 1 is a diagram showing a group of micromirrors. [Figure 7] FIG. 10 is an enlarged view showing the outline of the right end of the validity region. [Figure 8] FIG. 2 is an enlarged view showing a stripe region. [Figure 9] FIG. 10 is an enlarged view showing a part of the outline of an irradiation region group. [Figure 10] FIG. 10 is a diagram showing a group of micromirrors according to a comparative example. [Figure 11] FIG. 2 is an enlarged view showing a stripe region. [Figure 12A] 10A and 10B are diagrams for explaining a case where the movement amount of the irradiation area group in the sub-scanning direction is slightly increased in a comparative example. [Figure 12B] 10A and 10B are diagrams for explaining a case where the movement amount of the irradiation area group in the sub-scanning direction is slightly reduced in a comparative example. [Figure 13A] 9 is a diagram for explaining a case where the amount of movement of the irradiation area group in the sub-scanning direction is slightly increased in the configuration of FIG. 8. FIG. [Figure 13B] 9 is a diagram for explaining a case where the amount of movement of the irradiation area group in the sub-scanning direction is slightly reduced in the configuration of FIG. 8. FIG. [Figure 14] FIG. 1 illustrates a tilted DMD. [Figure 15] FIG. 2 is a diagram showing a valid region and an invalid region. [Figure 16] FIG. 10 is an enlarged view showing the arrangement of micromirrors near one step portion. [Figure 17] FIG. 2 is an enlarged view showing a stripe region. [Figure 18] FIG. 10 is an enlarged view showing a first step shape of the irradiation area group. [Figure 19] FIG. 10 is an enlarged view showing another example of the first step shape of the irradiation area group. DETAILED DESCRIPTION OF THE INVENTION

[0015] Fig. 1 is a perspective view showing the configuration of a pattern writing apparatus (hereinafter referred to as "writing apparatus") 1 according to one embodiment of the present invention. 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, and the Z direction is vertical.

[0016] The imaging device 1 is a direct imaging device that irradiates a photosensitive material of a substrate 9 with spatially modulated light and scans the irradiation area of ​​the light over the substrate 9 to draw a pattern on the substrate 9. The substrate 9, which is the object of imaging, is, for example, a plate-like member that is substantially rectangular in a plan view. The substrate 9 is, for example, a flexible printed wiring board. In this embodiment, a solder resist film, which is a photosensitive material, is provided over substantially the entire upper surface of the substrate 9 so as to cover the circuit pattern. The imaging device 1 draws a pattern of a solder resist layer on the solder resist film. In a post-process, processing such as development is performed to obtain a substrate 9 with a solder resist layer formed on the circuit pattern. The photosensitive material film is not limited to a solder resist film and may be, for example, a resist film used in forming a circuit pattern.

[0017] The imaging device 1 includes a stage 121, a stage moving mechanism 122, a light irradiation unit 13, and a control unit 14. The control unit 14 controls the stage moving mechanism 122, the light irradiation unit 13, etc. The stage 121 is a substantially flat plate-shaped holding unit that holds the substrate 9 in a horizontal position from below, below the light irradiation unit 13 (i.e., on the (-Z) side). The main surface (the surface to be imaged, hereinafter referred to as the "target surface 91") on the (+Z) side of the substrate 9 placed on the stage 121 is perpendicular to the Z direction and parallel to the X and Y directions. The stage 121 may be configured to grip the outer edge of the substrate 9, for example.

[0018] The stage moving mechanism 122 includes a support plate 123, a base plate 124, a base 125, a rotation mechanism 126, a main scanning mechanism 127, and a sub-scanning mechanism 128. The support plate 123 supports the stage 121 from below. The rotation mechanism 126 includes, for example, a linear motor and a rotation shaft. The linear motor includes a mover attached to the end of the stage 121 and a stator provided on the upper surface of the support plate 123. The rotation shaft is parallel to the Z direction and is provided in the center of the lower surface of the stage 121. When the linear motor is driven, the stage 121 rotates around the rotation shaft within a predetermined angle range.

[0019] The sub-scanning mechanism 128 has, for example, a linear motor and a pair of guide units. The linear motor has a mover attached to the lower surface of the support plate 123 and a stator provided on the upper surface of the base plate 124. The pair of guide units extend in the X direction and are provided between the support plate 123 and the base plate 124. When the linear motor is driven, the support plate 123 moves in the X direction along the guide units on the base plate 124.

[0020] The main scanning mechanism 127 has, for example, a linear motor and a pair of guide units. The linear motor has a mover attached to the lower surface of the base plate 124 and a stator provided on the upper surface of the base 125. The pair of guide units extend in the Y direction and are provided between the base plate 124 and the base 125. When the linear motor is driven, the base plate 124 moves in the Y direction along the guide units on the base 125. In other words, the main scanning mechanism 127 moves the substrate 9 and the stage 121 in the Y direction along the target surface 91 of the substrate 9.

[0021] In the following description, the Y direction is also referred to as the "main scanning direction," and the X direction perpendicular to the main scanning direction and along the target surface 91 of the substrate 9 is also referred to as the "sub-scanning direction." The driving sources of the rotation mechanism 126, the sub-scanning mechanism 128, and the main scanning mechanism 127 may be other than linear motors, and for example, a motor attached to a ball screw may be used. The stage movement mechanism 122 may be provided with a stage lifting mechanism that raises and lowers the stage 121 in the Z direction. Alternatively, the rotation mechanism 126 may be omitted.

[0022] The light irradiation unit 13 includes a plurality of drawing heads 131 arranged in the sub-scanning direction, and each drawing head 131 irradiates light onto the substrate 9. In the present embodiment, the number of drawing heads 131 is five, but it may be four or less, or six or more. The plurality of drawing heads 131 are supported above the stage 121 by a head support unit 119 provided across the stage 121.

[0023] FIG. 2 is a perspective view showing one drawing head 131. The multiple drawing heads 131 have approximately the same structure. A light source unit 136 and an illumination optical system 137 are connected to each drawing head 131. The light source unit 136 has a light source such as an LED, and emits light of a predetermined wavelength. The light source unit 136 may have other types of light sources. The illumination optical system 137 has, for example, a rod integrator and a lens. The light emitted from the light source unit 136 is guided to the drawing head 131 via the illumination optical system 137.

[0024] The drawing head 131 includes a light modulation unit 132 and a projection optical system 133. The light modulation unit 132 has a spatial light modulator. In this embodiment, the spatial light modulator is a DMD (Digital Micromirror Device) in which a plurality of micromirrors, which are a plurality of light modulation elements, are two-dimensionally arranged within a rectangular area. Light from the illumination optical system 137 is irradiated onto a plurality of light modulation elements (a plurality of micromirrors in this case) in the light modulation unit 132. In each light modulation element, the attitude of the micromirror that reflects light toward the projection optical system 133 (ON state) and the attitude of the micromirror that reflects light in a direction different from the projection optical system 133 (OFF state) can be switched under the control of the control unit 14.

[0025] Of the light irradiated onto the light modulation unit 132, light reflected by the light modulation elements in the ON state is incident on the projection optical system 133. That is, spatially modulated light from the light modulation unit 132 is emitted toward the projection optical system 133. The projection optical system 133 changes the magnification of the light to a predetermined magnification and guides it to the target surface 91 of the substrate 9. An image of the light modulation unit 132 is projected (formed) on the target surface 91. In the following description, the modulated light emitted from each drawing head 131 toward the substrate 9 is also referred to as "drawing light."

[0026] 3 is a diagram showing the DMD 21 included in the light modulation unit 132. The DMD 21 is a spatial light modulation device in which a plurality of micromirrors (hereinafter referred to as "micromirror group 212") are two-dimensionally arranged within a rectangular area on a silicon substrate 211, and the attitude (tilt angle) of each micromirror can be individually changed by electrostatic field action according to drawing data written in a memory cell corresponding to each micromirror. Light guided from the illumination optical system 137 is incident on the DMD 21 at an angle and uniformly illuminates the micromirror group 212. For example, the DMD 21 may be one having 768 rows and 1024 columns of micromirrors or one having 1080 rows and 1920 columns of micromirrors.

[0027] FIG. 4 is a diagram for explaining drawing of a pattern on a substrate 9 by a plurality of drawing heads 131. FIG. 5 is a diagram showing the flow of operations of the drawing apparatus 1. First, the main scanning mechanism 127 of FIG. 1 starts continuous movement (main scanning) of the stage 121 from the (+Y) side to the (-Y) direction (step S1). The movement of the stage 121 is movement of an irradiation area group, which will be described later. Then, when the stage 121 reaches a predetermined drawing start position (step S2), the control unit 14 controls the light irradiation by the DMD 21 (step S3). Thereafter, when the stage 121 reaches a predetermined drawing stop position, the light irradiation control ends (step S4), and the movement of the stage 121 in the main scanning direction also stops (step S5).

[0028] As a result, as shown in FIG. 3 , an area 810 (an area roughly indicated by a hatched rectangle) irradiated with the imaging light emitted from each imaging head 131 moves from the (−Y) side to the (+Y) side on the target surface 91 of the substrate 9, and a pattern is drawn in a strip-shaped area (hereinafter referred to as a “stripe area”) 811 extending in the main scanning direction on the target surface 91. The area 810 is a collection of minute irradiation areas corresponding to the micromirror group 212 of the DMD 21 (more precisely, the micromirrors used for imaging among the micromirror group 212 of the DMD 21), and therefore is hereinafter referred to as an “irradiation area group 810.” In the sub-scanning direction (X direction), gaps are provided between the irradiation area groups 810 of the multiple imaging heads 131, and therefore gaps also exist between the multiple stripe areas 811. Movement of the stage 121 in the main scanning direction relative to the imaging heads 131 also moves the irradiation area group 810 in the main scanning direction.

[0029] Next, the stage 121 is moved (sub-scanned) by a predetermined distance in the (-X) direction by the sub-scanning mechanism 128 (steps S6 and S7). The movement of the stage 121 in the sub-scanning direction relative to the drawing head 131 also moves the irradiation area group 810 in the sub-scanning direction. The movement distance of the stage 121 in the sub-scanning direction is slightly smaller than the width of the stripe area 811, but this is ignored in the drawing in Figure 4 (see the explanation for Figure 8 below).

[0030] Next, steps S1 to S5 are repeated while the stage 121 continuously moves from the (-Y) side to the (+Y) direction, and the group of irradiation areas 810 of the drawing light moves from the (+Y) side to the (-Y) direction on the target surface 91. As a result, a pattern is drawn in stripe areas 812 that are adjacent to each stripe area 811 on the (+X) side and extend in the main scanning direction. The stripe areas 812 partially overlap with the stripe areas 811. When the group of irradiation areas 810 reaches the end of the substrate 9 on the (-Y) side, the sub-scanning mechanism 128 moves the stage 121 a predetermined distance in the (-X) direction (steps S6 and S7).

[0031] Thereafter, steps S1 to S5 are further repeated while the stage 121 continuously moves from the (+Y) side to the (-Y) direction, and the group of irradiation regions 810 of the drawing light moves from the (-Y) side to the (+Y) side on the target surface 91. As a result, a pattern is drawn in stripe regions 813 that contact the (+X) side of each stripe region 812 and extend in the main scanning direction. Each stripe region 813 except for the stripe region 813 on the (+X) side also contacts the stripe region 811 located on the (+X) side. The stripe region 813 partially overlaps the stripe regions 811 and 812.

[0032] As described above, the control unit 14 controls the movement of the irradiation region group 810 by the stage moving mechanism 122 and the irradiation of light to each irradiation region of the irradiation region group 810 by the light irradiation unit 13, and irradiates each position on the substrate 9 with light while passing through the plurality of irradiation regions, thereby drawing a pattern on the substrate 9. In this embodiment, the stage 121 performs three consecutive relative movements in the main scanning direction with respect to the drawing head 131 (hereinafter simply referred to as "main scanning of the stage 121"), thereby completing the drawing of a pattern on the target surface 91.

[0033] In the drawing apparatus 1, a pattern may be drawn over the entire drawing target area by performing two or four or more main scans of the stage 121. Alternatively, the drawing heads 131 may be arranged in a staggered pattern in the main scanning direction while narrowing the intervals between the drawing heads 131 in the sub-scanning direction, thereby completing drawing of the pattern with one main scan of the stage 121. In this case, the sub-scanning mechanism 128 may be omitted.

[0034] FIG. 6 is a diagram showing the micromirror group 212 of the DMD 21. The micromirror group 212 has a large number of micromirrors arranged two-dimensionally, vertically and horizontally. Among these micromirrors, those in the hatched region 221 form an enabled region used for drawing, while those in the region marked with reference numeral 222 form a disabled region not used for drawing. The tilt of the micromirrors in the enabled region 221 is changeable, and they can be switched between irradiating a small irradiation region on the target surface 91 with light and not irradiating it with light. The tilt of the micromirrors in the disabled region 222 is fixed, and they do not irradiate the target surface 91 with light. The enabled region 221 and the disabled region 222 are realized by creating mask information for the DMD 21, i.e., by setting a bit for specifying whether each micromirror is enabled or disabled. Of the plurality of micromirrors which are the plurality of light modulation elements, the group of effective light modulation elements present in the effective area 221 corresponds to the group of irradiation areas (see reference numeral 810 in FIG. 4) which move on the substrate 9.

[0035] At the horizontal end of the validation area 221 in FIG. 6, the outline of the validation area 221 has a stepped shape that is inclined with respect to the vertical direction. FIG. 7 is an enlarged view of the outline of the right end of the validation area 221. The "stepped shape" means that the ends of multiple straight line portions 231 extending in the vertical direction are connected via short straight line portions (hereinafter referred to as "step portions") 232 extending in the left-right direction. In the example of FIG. 7, the vertical straight line portions 231 have a length corresponding to, for example, an arrangement of 10% of the number of micromirrors aligned in the vertical direction, and the horizontal step portions 232 have a length corresponding to an arrangement of 1% of the number of micromirrors aligned in the vertical direction.

[0036] 8 is an enlarged view of two adjacent stripe regions 831 and 832. In FIG. 8, the ranges of the stripe regions 831 and 832 are denoted by reference numerals 831 and 832. Note that the two stripe regions 831 and 832 show an example of a state in the middle of drawing, and do not necessarily correspond to FIG. 4. If the stripe region 831 in FIG. 8 corresponds to the stripe region 812 in FIG. 4 and the stripe region 832 in FIG. 8 corresponds to the stripe region 813 in FIG. 4, then to the right of the stripe region 832 there is a stripe region that was first drawn by another drawing head 131.

[0037] In FIG. 8 , the stripe region 831 on the left, which extends vertically (the main scanning direction), is an area where a pattern is drawn prior to the stripe region 832 on the right. In FIG. 8 , the irradiation region group 821 in the middle of drawing the stripe region 831 is indicated by an imaginary two-dot chain line, and the irradiation region group 822 in the middle of drawing the stripe region 832 is indicated by a solid line. Hereinafter, when distinguishing between the irradiation region group 821 and the irradiation region group 822, these will be referred to as the “preceding irradiation region group 821” and the “subsequent irradiation region group 822.” Arrow 825 indicates the movement direction of the preceding irradiation region group 821, and arrow 826 indicates the movement direction of the subsequent irradiation region group 822. In addition, in FIGS. 6 and 8 , the shape of the validation region 221 and the shapes of the irradiation region groups 821 and 822 are depicted in the same manner for ease of understanding. However, due to the influence of the optical system, even when the validation region 221 and the irradiation region groups 821 and 822 are superimposed, the vertical and / or horizontal directions may be reversed.

[0038] The stripe region 831 is a region that is irradiated with light by controlling the light irradiation from the light irradiation unit 13 to the preceding irradiation region group 821 and moving the preceding irradiation region group 821 parallel to the main scanning direction in steps S1 to S5 of Fig. 5 under the control of the control unit 14. Hereinafter, the stripe region 831 will be referred to as the "preceding stripe region 831." The stripe region 832 is a region that is irradiated with light by controlling the light irradiation from the light irradiation unit 13 to the following irradiation region group 822 and moving the following irradiation region group 822 parallel to the main scanning direction in steps S1 to S5 after steps S6 and S7 under the control of the control unit 14. Hereinafter, the stripe region 832 will be referred to as the "following stripe region 832."

[0039] FIG. 9 is an enlarged view of a portion of the contour of the preceding irradiation region group 821, at the end in the sub-scanning direction (the end on the right side in FIG. 8). Since the shape of the irradiation region group corresponds to the shape of the validation region 221 in FIG. 6, the shape of the contour in FIG. 9 is the same as the shape shown in FIG. 7. That is, at the end in the sub-scanning direction of the preceding irradiation region group 821, the contour of the preceding irradiation region group 821 has a staircase shape inclined with respect to the vertical direction. Specifically, the ends of a plurality of straight line portions 841 extending in the main scanning direction are connected via short straight line portions (hereinafter referred to as "step portions") 842 extending in the sub-scanning direction. In other words, the staircase shape is a shape in which straight line portions 841 extending in the main scanning direction and step portions 842 extending in a direction intersecting the main scanning direction are repeated. In the example of FIG. 9, the straight line portion 841 is 10% of the length of the irradiation region group in the main scanning direction.

[0040] Of the contours of the preceding irradiation area group 821, the shape of the end in the sub-scanning direction opposite to that in FIG. 9 (the left end in FIG. 8) is the same as the right end rotated 180°. Naturally, of the contours of the subsequent irradiation area group 822, the shape of the left end in FIG. 8 is also the same as the right end rotated 180°. That is, in terms of design, the preceding irradiation area group 821 and the subsequent irradiation area group 822 can be arranged side by side without any gaps. However, as will be described later, the shapes may be slightly modified in consideration of the effect of overlapping irradiation by the preceding irradiation area group 821 and the subsequent irradiation area group 822. The above phrase "can be arranged side by side without any gaps" is an expression that ignores such slight shape modifications.

[0041] Hereinafter, the staircase shape at the right end of the outline of the irradiation area group in FIG. 8 will be referred to as the "first staircase shape," and the first staircase-shaped portion of the outline will be referred to as the "first staircase-shaped portion." Also, the staircase shape at the left end of the outline of the irradiation area group in FIG. 8 will be referred to as the "second staircase shape," and the second staircase-shaped portion of the outline will be referred to as the "second staircase-shaped portion." In FIG. 8, the first staircase-shaped portion is given the symbol 823, and the second staircase-shaped portion is given the symbol 824. The first staircase shape and the second staircase shape are shapes that complement each other and allow the preceding irradiation area group 821 and the subsequent irradiation area group 822 to be aligned side by side without any gaps at the same position in the main scanning direction.

[0042] As shown in FIG. 8, the range in the sub-scanning direction of the first staircase-shaped portion 823 of the preceding irradiation region group 821 and the range in the sub-scanning direction of the second staircase-shaped portion 824 of the subsequent irradiation region group 822 are the same. In FIG. 8, this range is indicated by reference numeral 833. In the range indicated by reference numeral 833, light irradiation performed in the range of the moving preceding irradiation region group 821 (hereinafter, light irradiation performed in the range of the moving irradiation region group will be referred to as "light irradiation by the irradiation region group") and light irradiation by the subsequent irradiation region group 822 overlap. In other words, the region extending in the main scanning direction indicated by reference numeral 833 is an overlapping region where the preceding stripe region 831 irradiated with light by the preceding irradiation region group 821 and the subsequent stripe region 832 irradiated with light by the subsequent irradiation region group 822 partially overlap. In the following description, the overlapping region will be indicated by reference numeral 833. The area of ​​the stripe regions 831 and 832 excluding the overlapping region 833 (the area excluding the overlapping regions that exist on both sides of each stripe region in principle, the area indicated by reference numeral 834 in FIG. 8) is called the "non-overlapping region." The non-overlapping region 834 is a region through which only one of the preceding irradiation region group 821 and the following irradiation region group 822 passes.

[0043] The preceding irradiation region group 821 passes continuously over each position of the non-overlapping region 834 of the preceding stripe region 831 in a constant time. The following irradiation region group 822 also passes continuously over each position of the non-overlapping region 834 of the following stripe region 832 in the same constant time. Furthermore, the total time that the preceding irradiation region group 821 and the following stripe region 832 pass over each position of the overlapping region 833 is the same constant time. Therefore, assuming that the two irradiation region groups 821 and 822 always irradiate the target surface 91 with the maximum amount of light, the same amount of light is irradiated at each position of the non-overlapping region 834 and the overlapping region 833. In other words, the amount of light irradiation per unit area in the non-overlapping region 834 and the overlapping region 833 is constant. This allows appropriate patterns to be written in the non-overlapping region 834 and the overlapping region 833.

[0044] Fig. 10 is a diagram showing a micromirror group 212a according to a comparative example, and corresponds to Fig. 6. Invalidation areas 242 are provided at the upper right and lower left of the micromirror group 212a, and the other areas are activation areas 241. Each invalidation area 242 is a vertically elongated rectangle (strip-shaped), and the vertical length is 50% of the vertical length of the micromirror group 212a.

[0045] 10, the outline of the validated area 241 has a shape that includes one step. That is, the shape of the outline of the validated area 241 at the horizontal end is such that two straight line portions 251 extending vertically are connected via one short straight line portion (hereinafter referred to as "step portion") 252 extending horizontally. Hereinafter, the shape formed by the two straight line portions 251 and one step portion 252 will be referred to as the "step portion."

[0046] FIG. 11 is an enlarged view of two adjacent stripe regions 861, 862, and corresponds to FIG. 8. The ranges of the stripe regions 861, 862 are designated by the reference symbols 861, 862. In FIG. 11, the stripe region 861 on the left side extending vertically is a preceding stripe region in which a pattern is written prior to the subsequent stripe region 862 on the right side. The stripe region 862 on the right side is a subsequent stripe region. An arrow 855 indicates the direction of movement of the preceding irradiation region group 851, and an arrow 856 indicates the direction of movement of the subsequent irradiation region group 852.

[0047] The shape of the irradiation area groups 851 and 852 corresponds to the shape of the validation area 241 in Fig. 10, and each of the irradiation area groups 851 and 852 has the above-mentioned step-shaped portion. Hereinafter, the shape of the right end of the outline of the preceding irradiation area group 851 in Fig. 11 will be referred to as a "first step-shaped portion 853," and the shape of the left end of the outline of the subsequent irradiation area group 822 in Fig. 11 will be referred to as a "second step-shaped portion 854."

[0048] As shown in FIG. 11, the range of the first stepped portion 853 in the sub-scanning direction and the range of the second stepped portion 854 in the sub-scanning direction are the same. In FIG. 11, this range is indicated by reference numeral 863. The range indicated by reference numeral 863 is an overlapping region where the light irradiation by the preceding irradiation region group 851 and the light irradiation by the subsequent irradiation region group 852 overlap. In the following description, the region of the stripe regions 861, 862 excluding the overlapping region 863 (the region excluding the overlapping regions that are generally present on both sides of each stripe region, the region indicated by reference numeral 864 in FIG. 11) is referred to as a "non-overlapping region." The non-overlapping region 864 is a region through which only one of the preceding irradiation region group 851 and the subsequent irradiation region group 852 passes.

[0049] The preceding irradiation region group 851 passes continuously through each position of the non-overlapping region 864 of the preceding stripe region 861 in a constant time. The following irradiation region group 852 also passes continuously through each position of the non-overlapping region 864 of the following stripe region 862 in the same constant time. In contrast, at each position of the overlapping region 863, the preceding irradiation region group 851 passes through in half the constant time, and the following irradiation region group 852 also passes through in half the constant time. The total time taken for the irradiation region groups 851 and 852 to pass through is the same constant time. Therefore, assuming that the two irradiation region groups 851 and 852 always irradiate the target surface 91 with the maximum amount of light, the same amount of light is irradiated at each position of the non-overlapping region 864 and the overlapping region 863. In other words, the amount of light irradiated per unit area in the non-overlapping region 864 and the overlapping region 863 is constant.

[0050] 12A is a diagram illustrating a change in the amount of light irradiation when the amount of movement of the irradiation area group in the sub-scanning direction is slightly increased in a comparative example. In FIG. 12A, a preceding irradiation area group 851 and a following irradiation area group 852 are virtually shown side by side. When the amount of movement of the irradiation area group in the sub-scanning direction is slightly greater than the design value, a gap occurs between the linear portion of the first stepped portion 853 extending in the main scanning direction and the linear portion of the second stepped portion 854 extending in the main scanning direction. In FIG. 12A, the range of the gap is indicated by reference numeral 865. At each position within the range 865, only one of the preceding irradiation area group 851 and the following irradiation area group 852 passes through. Since the length of the linear portion is 50% of the length of the irradiation area group in the main scanning direction (see linear portion 251 in FIG. 10), the time during which the irradiation area group passes through is 50% of the time of the other ranges.

[0051] 12B is a diagram illustrating a change in the amount of light irradiation when the amount of movement of the irradiation region group in the sub-scanning direction is slightly reduced in a comparative example. In FIG. 12B, the preceding irradiation region group 851 and the subsequent irradiation region group 852 are shown side by side, as in FIG. 12A. When the amount of movement of the irradiation region group in the sub-scanning direction is slightly smaller than the design value, an overlapping region occurs between the linear portion of the first stepped portion 853 extending in the main scanning direction and the linear portion of the second stepped portion 854 extending in the main scanning direction. In FIG. 12B, the range of the overlapping region is indicated by reference numeral 866. Both the preceding irradiation region group 851 and the subsequent irradiation region group 852 pass through each position within the range 866. Since the length of the linear portion is 50% of the length of the irradiation region group in the main scanning direction, the time spent passing through the linear portion is 150% of the time spent passing through the linear portion.

[0052] FIG. 13A is a diagram illustrating a change in the amount of light irradiation when the amount of movement of the irradiation area group in the sub-scanning direction of the irradiation area group in FIG. 8 increases slightly. In FIG. 13A , the preceding irradiation area group 821 and the subsequent irradiation area group 822 are also shown side by side. When the amount of movement of the irradiation area group in the sub-scanning direction increases slightly from the design value, a gap occurs between a linear portion 841 (see FIG. 9 ) extending in the main scanning direction of the first staircase-shaped portion 823 and a linear portion extending in the main scanning direction of the second staircase-shaped portion 824. In FIG. 13A , the range of one gap is indicated by reference numeral 835. In reality, there are ten ranges 835. At each position within the range 835, the irradiation area group does not pass through a portion of the gap in the main scanning direction that corresponds to the length of the gap. Because the length of the linear portion is 10% of the length of the irradiation area group in the main scanning direction, the time the irradiation area group passes through is 90% of the time the other ranges pass through.

[0053] FIG. 13B is a diagram illustrating a change in the amount of light irradiation when the amount of movement of the irradiation area group in the sub-scanning direction of the irradiation area group in FIG. 8 is slightly reduced. In FIG. 13B, the preceding irradiation area group 821 and the subsequent irradiation area group 822 are shown side by side, as in FIG. 13A. When the amount of movement of the irradiation area group in the sub-scanning direction is slightly reduced compared to the design value, an overlapping area occurs between the linear portion of the first staircase-shaped portion 823 extending in the main scanning direction and the linear portion of the second staircase-shaped portion 824 extending in the main scanning direction. In FIG. 13B, the range of one overlapping area is indicated by reference numeral 836. In reality, there are ten ranges 836. Both the preceding irradiation area group 821 and the subsequent irradiation area group 822 pass through each position within the range 836, and the length of the linear portion is 10% of the length of the irradiation area group in the main scanning direction, so the passing time is 110% of the other ranges.

[0054] As described above, in the irradiation area groups 821 and 822 of FIG. 8, the portion of the contour that passes through the overlapping area 833 is stepped, so that the change in the irradiation amount in the sub-scanning direction is dispersed more than in the comparative example of FIG. 11. This makes it possible to reduce the influence of errors in the movement amount of the irradiation area group in the sub-scanning direction on the drawn pattern compared to the comparative example. As a result, it is possible to appropriately draw high-resolution patterns. For example, when drawing a thin line extending in the sub-scanning direction, the line becomes thin in the range 865 in the comparative example of FIG. 12A, but the line hardly becomes thin in the range 835 in FIG. 13A. Furthermore, in the comparative example of FIG. 12B, the line becomes thick in the range 866, but the line hardly becomes thick in the range 836 in FIG. 13B.

[0055] The length of each of the straight line portions included in the first and second staircase shapes is preferably 20% or less of the length of the irradiation area group in the main scanning direction (more precisely, the length of the irradiation area group when cut by a straight line parallel to the main scanning direction in the non-overlapping area; the same applies below). More preferably, the length of the straight line portion is 10% or less of the length of the irradiation area group in the main scanning direction. The shorter the straight line portion, the more the fluctuation in the amount of light irradiation can be suppressed, but if it is too short, the width of the overlapping area in the sub-scanning direction will increase, so the length of the straight line portion is preferably 1% or more of the length of the irradiation area group in the main scanning direction.

[0056] To make the seams between the stripe regions less noticeable in the written pattern, the width of the overlapping region 833 in the sub-scanning direction is preferably 0.1% or more, and more preferably 1% or more, of the width of the non-overlapping region 834 in the sub-scanning direction. Furthermore, from the viewpoint of writing efficiency, the width of the overlapping region 833 in the sub-scanning direction is preferably 20% or less, and more preferably 10% or less, of the width of the non-overlapping region 834 in the sub-scanning direction. The same applies to Figure 17 and other modified examples described below. Of course, the above numerical ranges exclude the stripe regions located at the extreme ends of the writing region.

[0057] In the imaging device 1, the DMD may be slightly tilted, as in the above-mentioned Japanese Patent Application Laid-Open No. 2008-70506 (Patent Document 1). That is, the array of micromirrors in the DMD is tilted relative to the main scanning direction. The entire disclosure of Patent Document 1 is incorporated herein by reference. By tilting the DMD, the group of irradiation areas is also tilted relative to the main scanning direction. As a result, the positions of the centers of the microirradiation areas corresponding to each micromirror in the sub-scanning direction become closer than the pitch of the micromirrors when they are not tilted. As a result, the unit of change in the width of the drawing line can be made smaller than the pitch of the micromirrors. However, the size of one microirradiation area is relatively large compared to the pitch of the centers of the microirradiation areas in the sub-scanning direction.

[0058] FIG. 14 is a diagram illustrating a tilted DMD 21, showing an enlarged view of a portion of a micromirror 213 included in a micromirror group 212. As already explained, in the DMD 21, a plurality of micromirrors 213, which are a plurality of light modulation elements, are arranged in a rectangular shape in row and column directions that are perpendicular to each other. In FIG. 14, the vertical direction corresponds to the main scanning direction, and the horizontal direction corresponds to the sub-scanning direction. In the example of FIG. 14, when focusing on one micromirror 213, the position of the micromirror 213 located four positions below the micromirror 213 of interest in a direction roughly along the vertical direction is located directly below the micromirror 213 adjacent to the right of the micromirror 213 of interest. Hereinafter, this type of tilt will be referred to as a "4:1 tilt."

[0059] Fig. 15 is a diagram showing the enabled region 221 and the disabled region 222 in the micromirror group 212 shown in Fig. 14. As already explained, the tilt of the micromirrors present in the enabled region 221 is changeable, and can be changed between a state in which light is irradiated onto a minute irradiation region on the target surface 91 and a state in which light is not irradiated. The tilt of the micromirrors present in the disabled region 222 is fixed, and they do not irradiate light onto the target surface 91.

[0060] 15, as in FIG. 6, the outline of the validation area 221 at its horizontal ends has a stepped shape that is inclined with respect to the vertical direction. That is, the ends of multiple straight line segments extending in the vertical direction are connected via stepped portions, which are short straight line segments extending in the horizontal direction. Because the DMDs 21 are arranged with a 4:1 inclination, the vertical straight line segments are, macroscopically, straight lines that extend approximately vertically. In the example of FIG. 15, the length of one straight line segment is 10% of the vertical length of the micromirror group 212 corresponding to the main scanning direction, i.e., the length of the micromirror group 212 when cut along a straight line extending in the vertical direction at a position excluding the stepped portion.

[0061] FIG. 16 is an enlarged view showing the arrangement of the micromirrors 213 near one step portion 232 in the activation area 221. The linear portions 231 located above and below the step portion 232 are jagged due to the inclination of the micromirror group 212. Focusing on the micromirror designated by reference numeral 213a in FIG. 16, the area below the micromirror 213a is the invalidation area 222, and the micromirror 213b adjacent to it on the left belongs to the activation area 221. The four micromirrors 213 located vertically below the micromirror 213b belong to the activation area 221, and the area below the bottommost micromirror 213c is the invalidation area 222. Thus, with a 4:1 inclination, the micromirrors 213 are arranged in the linear portion 231 such that for every four micromirrors moving downward, one micromirror is shifted horizontally. In the step portion 232 in the example of FIG. 16, the micromirrors 213 in the activation area 221 are aligned in a linear fashion inclined approximately horizontally. Of course, in the step portion 232 as well, the micromirrors 213 may be arranged so that for every four micromirrors to the right, one micromirror is shifted downward.

[0062] In this way, vertical straight portion 231 may be a straight line extending in approximately the vertical direction when viewed macroscopically, and may have a minute step (for example, a step the size of one micromirror) when viewed microscopically (i.e., enlarged). Horizontal step portion 232 does not need to be perpendicular to straight portion 231, and may extend in a direction intersecting straight portion 231. Furthermore, step portion 232 may be a straight line when viewed macroscopically, and does not need to be a straight line when viewed microscopically.

[0063] Figure 17 is an enlarged view of two adjacent stripe regions 831, 832, and corresponds to Figure 8. Figure 17 is the same as Figure 8 except for the shape of the irradiation region group, and therefore elements in Figure 17 that correspond to those in Figure 8 are given the same reference numerals as in Figure 8. In Figure 17, the stripe region 831 on the left side extending vertically is a preceding stripe region in which a pattern is written prior to the stripe region 832 on the right side. The stripe region 832 on the right side is a succeeding stripe region.

[0064] 16, the multiple regions on the target surface 91 corresponding to the multiple micromirrors 213 are arranged in a rectangular shape with row and column directions that are perpendicular to each other. The column direction is inclined with respect to the main scanning direction. The effective light modulation element groups included in the validation area 221 correspond to the irradiation area groups 821 and 822. That is, the staircase shape (first staircase shape) at the right end and the staircase shape (second staircase shape) at the left end of the outlines of the irradiation area groups 821 and 822 are shapes that alternate between straight line portions extending in the main scanning direction and step portions extending in a direction intersecting the main scanning direction.

[0065] 16, vertical straight line portion 841 may be a straight line extending approximately in the vertical direction when viewed macroscopically, and may have a minute step when viewed microscopically (for example, a step the size of one minute irradiation area). Step portion 842 does not need to be perpendicular to straight line portion 841, and may extend in a direction intersecting straight line portion 841. Step portion 842 may be a straight line when viewed macroscopically, and does not need to be a straight line when viewed microscopically.

[0066] In Figures 15 and 17, the shape of the validation area 221 and the shapes of the irradiation area groups 821 and 822 are drawn the same to make it easier to understand, but due to the influence of the optical system, even when the validation area 221 and the irradiation area groups 821 and 822 are superimposed, the vertical and / or horizontal directions may be reversed.

[0067] Of the contours of the preceding irradiation area group 821, the staircase shape (second staircase shape) at the left end is the same as the staircase shape (first staircase shape) at the right end rotated 180 degrees. The same is true for the contours of the subsequent irradiation area group 822. Therefore, the preceding irradiation area group 821 and the subsequent irradiation area group 822 can be aligned side by side without any gaps at the same position in the main scanning direction. In this way, the first staircase shape and the second staircase shape are complementary to each other. However, as will be described later, the shapes may be slightly modified in consideration of the influence of overlapping irradiation by the preceding irradiation area group 821 and the subsequent irradiation area group 822. The above phrase "aligning side by side without any gaps" is an expression that ignores such slight shape modifications.

[0068] 8, the range in the sub-scanning direction of the first staircase-shaped portion 823 of the preceding irradiation region group 821 coincides with the range in the sub-scanning direction of the second staircase-shaped portion 824 of the following irradiation region group 822. The range marked with reference numeral 833 is an overlapping region where the light irradiation by the moving preceding irradiation region group 821 and the light irradiation by the following irradiation region group 822 overlap. In other words, the overlapping region 833 is a region where the stripe region 831 and the stripe region 832 overlap.

[0069] The preceding irradiation region group 821 passes continuously over a fixed time period through each position in the non-overlapping region 834 of the preceding stripe region 831. The following irradiation region group 822 also passes continuously over the same fixed time period through each position in the non-overlapping region 834 of the following stripe region 832. Since the first staircase shape and the second staircase shape are complementary to each other, the total time it takes for the preceding irradiation region group 821 and the following stripe region 832 to pass over each position in the overlapping region 833 is the same fixed time period.

[0070] The direction in which the first staircase shape and the second staircase shape extend is closer to the main scanning direction than to the column direction of the irradiation area groups 821 and 822 (i.e., the direction on the target surface 91 corresponding to the column direction of the micromirror group 212). In other words, the direction in which the first staircase shape and the second staircase shape extend is a direction between the main scanning direction and the column direction (i.e., the direction in which the main scanning direction is tilted in accordance with the tilt of the spatial light modulator).

[0071] 17, as in the explanation with reference to FIGS. 12A to 13B, in the case of irradiation area groups 821 and 822, the portions of the contours that pass through overlapping area 833 are stepped, so that the influence of errors in the amount of movement of the irradiation area group in the sub-scanning direction on the drawn pattern can be minimized. The length of the straight line portion included in the stepped shape is preferably 20% or less of the length of the irradiation area group in the main scanning direction (more precisely, the length when the irradiation area group is cut by a straight line extending in the main scanning direction in the non-overlapping area). More preferably, the length of the straight line portion is 10% or less of the length of the irradiation area group in the main scanning direction. Also, preferably, the length of the straight line portion is 1% or more of the length of the irradiation area group in the main scanning direction.

[0072] When the DMD 21 is tilted, the irradiation area corresponding to one micromirror 213 is large relative to the unit of changeable width of the drawing line in the sub-scanning direction, so the fluctuation in the amount of light irradiation in the sub-scanning direction due to errors in the amount of movement of the irradiation area group in the sub-scanning direction is gradual.

[0073] The rendering device 1 and its operation can be modified in various ways.

[0074] In the example of FIG. 14, the DMD 21 is arranged with a 4:1 tilt, but the tilt may be changed in various ways, such as 8:1, 14:1, 16:1, etc. FIG. 18 is an enlarged view of the first step shape of the irradiation area group when the DMD 21 is arranged with a 8:1 tilt. Each square in FIG. 18 represents an irradiation area corresponding to one micromirror 213. In the linear portion 841, when focusing on the target irradiation area 845a, the irradiation area 845c, which is located eight areas below the target irradiation area 845b adjacent to the left of the target irradiation area 845a in the vertical direction, is located directly below the target irradiation area 845a. In the stepped portion 842, eight irradiation areas are arranged in a direction approximately along the sub-scanning direction.

[0075] FIG. 19 shows another example of the first step shape of the irradiation area group when the DMD 21 is arranged with an 8:1 tilt. Of the 16 irradiation areas shown by thick lines in the center of FIG. 19, the top eight irradiation areas and the bottom eight irradiation areas are positioned exactly one above the other, forming a straight line portion 841, as in FIG. 18. However, the bottom eight thick irradiation areas and the eight irradiation areas further below them are arranged consecutively in the column direction, which corresponds to being positioned one irradiation area to the right, forming a pseudo-step portion 842. In other words, by arranging the irradiation areas consecutively in the column direction, a step portion 842 with a width equivalent to one irradiation area is formed. In FIG. 19, the lines corresponding to the straight line portion 841 and the step portion 842 are indicated by two-dot chain lines.

[0076] However, if the entire edge of the contour of the irradiation area group in the sub-scanning direction is parallel to the column direction, the relationship between the straight line portion 841 and the step portion 842 becomes unclear, and such a contour is not considered to have a shape that repeats straight line portions extending in the main scanning direction and step portions extending in a direction intersecting the main scanning direction. In other words, if the entire micromirror group 212 of the DMD 21 belongs to the validity area and an irradiation area group is provided corresponding to this, it is considered that no pseudo step portion exists.

[0077] 19 is an example in which extremely small step portions 842 are provided between straight line portions 841. Therefore, it is also possible to regard the entire staircase shape as an inclined straight line. In this case, the portion of the outline of the preceding irradiation region group 821 that passes through the overlapping region 833 can be regarded as a first inclined straight line portion extending in a direction between the main scanning direction and the column direction (the direction in which the main scanning direction is inclined in accordance with the inclination of the spatial light modulator), and it can also be expressed that the portion of the outline of the subsequent irradiation region group 822 that passes through the overlapping region 833 is a second inclined straight line portion that complements the first inclined straight line portion, i.e., a second inclined straight line portion with the same inclination as the first inclined straight line portion.

[0078] In the above description, the contour shape of the preceding irradiation region group 821 and the contour shape of the following irradiation region group 822 in the overlap region 833 are described as complementary shapes. That is, at each position in the non-overlapping region 834 and the overlap region 833, the time it takes for one irradiation region group to pass through is the same as the total time it takes for two irradiation region groups to pass through. However, depending on the photosensitive material to be irradiated with light, the degree of exposure may be more advanced when irradiated with light twice compared to when irradiated with light once. In such cases, the contour shapes of the irradiation region groups 821 and 822 may be modified so that the total time it takes for the two irradiation region groups to pass through in the overlap region 833 is slightly shorter than the time it takes for one irradiation region to pass through in the non-overlapping region 834. The above description ignores such modifications. For example, the phrase "the first stepwise shape and the second stepwise shape are complementary shapes" in the above description does not mean that modifications to the contour shapes of the irradiation region groups are excluded.

[0079] In the above description, the length of each straight line portion and the size of each step portion of the staircase shape are constant, but these do not have to be constant. Even if the staircase shape has straight line portions of various lengths, the preferred length of each straight line portion is 1% to 20% of the cut length when the irradiation area group is cut by a straight line parallel to the main scanning direction.

[0080] The number of drawing heads 131 may be one or more. When two or more drawing heads 131 are provided in the light irradiation unit 13, the preceding irradiation area group 821 and the following irradiation area group 822 may be irradiation area groups corresponding to different drawing heads 131. Alternatively, multiple drawing heads 131 may be densely arranged in the sub-scanning direction while being shifted forward and backward in the main scanning direction, so that drawing on all stripe areas can be completed in one main scanning pass.

[0081] The light irradiation unit 13 that irradiates the object with light can be changed in various ways. For example, a PLV (Planar Light Valve) may be used instead of a DMD. The outline shape of the irradiation area group onto which light is irradiated from the light irradiation unit 13 can be easily formed into a desired shape by providing an activation area 221 and an inactivation area 222 on a two-dimensional spatial light modulator. However, the outline shape of the irradiation area group may be set by a method other than setting the activation area 221 and the inactivation area 222. For example, an arrangement of spatial light modulation elements that matches the shape of the irradiation area group may be used.

[0082] In the above embodiment, the stage moving mechanism 122 functions as an irradiation area moving mechanism that moves the irradiation area group on the object, but the irradiation area moving mechanism can be provided in various forms. For example, a mechanism that moves the light irradiation unit 13 relative to the object may be provided as the irradiation area moving mechanism. Both a mechanism that moves the light irradiation unit 13 relative to the object and a mechanism that moves the object relative to the light irradiation unit 13 may be provided as the irradiation area moving mechanism. The irradiation area moving mechanism moves the object relatively to the light irradiation unit 13, thereby moving the irradiation area group on the object.

[0083] As described above, the lithography apparatus 1 may be used to draw patterns other than solder resist layer patterns. Furthermore, the substrate 9 may be a semiconductor substrate, a glass substrate, or the like, in addition to a printed wiring board. The target of the lithography apparatus according to the present invention is not limited to an object having a so-called photosensitive material. Furthermore, the target on which the lithography apparatus 1 draws a pattern by irradiating light is not limited to a substrate. For example, the lithography apparatus 1 may be employed as an apparatus for drawing a pattern on each layer of a modeling material in a three-dimensional modeling device. In this case, the target is a layer of fine particles or liquid such as ceramics, synthetic resin, metal powder, or engineering plastic, and the modeling material melts and solidifies or solidifies when a pattern is drawn by irradiating light. Of course, the lithography apparatus according to the present invention can be used for various other pattern drawing applications.

[0084] The configurations in the above-described embodiment and each modification may be combined as appropriate as long as they are not mutually contradictory. [Explanation of symbols]

[0085] 1. Pattern drawing device 9. Substrate (object) 13 Light irradiation unit 14 Control Unit 21 DMD (Spatial Light Modulator) 122 Stage movement mechanism (irradiation area movement mechanism) 213 Optical Modulator 221 Validation Area 810 Irradiation area group 821 Preliminary irradiation area group 822 Subsequent Irradiation Area Group 823 1st staircase shape part 824 2nd staircase shape part 831 Leading Stripe Area 832 Subsequent stripe area 833 Duplicate area 834 Non-overlapping area 841 Straight section 842 Step S1~S7 steps

Claims

1. A pattern drawing device that draws a pattern on an object by irradiating the object with light, a light irradiation unit that irradiates light onto an object; an irradiation area moving mechanism that moves an irradiation area group onto which light is irradiated from the light irradiating unit on the object; a control unit that controls the movement of the irradiation area group and the irradiation of light onto each irradiation area of ​​the irradiation area group, and performs drawing on the object by irradiating each position on the object with light while passing through a plurality of irradiation areas; Equipped with under the control of the control unit, light irradiation from the light irradiation unit to the preceding irradiation region group is controlled and the preceding irradiation region group is moved parallel to the main scanning direction, thereby irradiating light onto a preceding stripe region on the object, and light irradiation from the light irradiation unit to the subsequent irradiation region group is controlled and the subsequent irradiation region group is moved parallel to the main scanning direction, thereby irradiating light onto a subsequent stripe region that is adjacent to the preceding stripe region and partially overlaps with it in an overlapping region, the preceding irradiation region group or the following irradiation region group passes continuously at a fixed time through each position of the non-overlapping region in the preceding stripe region and the following stripe region; a portion of the outline of the preceding irradiation region group that passes through the overlap region has a first staircase shape that alternates between a straight line portion extending in the main scanning direction and a step portion extending in a direction intersecting the main scanning direction, a portion of the contour of the subsequent irradiation region group that passes through the overlap region has a second step shape that complements the first step shape, A pattern writing device in which any of the straight line portions included in the first staircase shape and the second staircase shape is 1% to 20% of the cutting length when the preceding irradiation area group and the subsequent irradiation area group are cut by a straight line parallel to the main scanning direction in the non-overlapping area.

2. 2. The pattern writing apparatus according to claim 1, A pattern drawing device in which the light irradiation unit has a spatial light modulator in which a plurality of light modulation elements are arranged two-dimensionally within a rectangular area, and a group of effective light modulation elements among the plurality of light modulation elements corresponds to the group of irradiation areas on the object.

3. 3. The pattern writing apparatus according to claim 2, The pattern writing device, wherein the plurality of light modulation elements are a plurality of micromirrors whose attitudes can be changed individually.

4. 4. The pattern drawing apparatus according to claim 2, wherein: a plurality of regions on the object corresponding to the plurality of light modulation elements are arranged in a rectangular shape in row and column directions that are perpendicular to each other, the column direction is inclined with respect to the main scanning direction, A pattern writing apparatus in which the direction in which the first staircase shape and the second staircase shape extend is aligned with the main scanning direction rather than the column direction.

5. 2. The pattern writing apparatus according to claim 1, A pattern writing apparatus, wherein the width of the overlapping region is 0.1% to 20% of the width of the non-overlapping region.

6. A pattern drawing method for drawing a pattern on an object by moving an irradiation area group onto which light is irradiated on an object while controlling the irradiation of light to each irradiation area of ​​the irradiation area group, and irradiating each position on the object with light while passing through a plurality of irradiation areas, a step of irradiating a preceding stripe region on the object with light by controlling irradiation of the preceding irradiation region group with light and moving the preceding irradiation region group parallel to a main scanning direction; a step of controlling the irradiation of light onto a subsequent irradiation region group and moving the subsequent irradiation region group parallel to the main scanning direction, thereby irradiating light onto a subsequent stripe region adjacent to the preceding stripe region and partially overlapping the preceding stripe region in an overlapping region; Equipped with the preceding irradiation region group or the following irradiation region group passes continuously at a fixed time through each position of the non-overlapping region in the preceding stripe region and the following stripe region; a portion of the outline of the preceding irradiation region group that passes through the overlap region has a first staircase shape that alternates between a straight line portion extending in the main scanning direction and a step portion extending in a direction intersecting the main scanning direction, a portion of the contour of the subsequent irradiation region group that passes through the overlap region has a second step shape that complements the first step shape, a pattern writing method in which any of the straight line portions included in the first staircase shape and the second staircase shape is 1% to 20% of the cutting length when the preceding irradiation area group and the subsequent irradiation area group are cut by a straight line parallel to the main scanning direction in the non-overlapping area.

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