Optical apparatus and drawing apparatus

Abstract

The invention provides an optical apparatus and a drawing apparatus capable of suppressing condensation and cooling a digital micromirror device. An optical modulation unit (44) of an optical device has a DMD (6) and a cooling unit (7) that cools the DMD (6). The cooling unit (7) has a first discharge flow path (764) and a first supply flow path (765). The first discharge flow path (764) cools the DMD6 by forming a gas flow along a (-Z)-side main surface (631) of the DMD cover section (63) by discharging a gas from the first discharge port (763). The first supply flow path (765) connects a gas supply source and the first discharge flow path (764), and guides compressed air discharged from the gas supply source to the first discharge flow path (764). The flow path cross-sectional area of the first supply flow path (765) is smaller than the flow path cross-sectional area of the first discharge flow path (764). Consequently, the DMD (6) can be cooled while suppressing condensation.

Description

Technical Field

[0001] The present invention relates to an optical device for irradiating modulated light onto an object, and a drawing device having the optical device and irradiating light onto a substrate to draw a pattern.

[0002] [Reference to related applications]

[0003] This application claims the benefit of priority of Japanese patent application JP2023-129334 filed on August 8, 2023, and incorporates the entire disclosure of that application into this application. Background Art

[0004] Conventionally, when drawing patterns on printed circuit boards, semiconductor substrates, etc. (hereinafter referred to as "substrates"), a drawing device is used that irradiates a photosensitive material formed on the substrate with modulated light and directly draws the pattern by scanning the irradiated area with the light.

[0005] In such a drawing device, a digital micromirror device (DMD) is used as one of the light modulators for modulating light in a drawing head that emits light toward a substrate. When the drawing device is in operation, the temperature of the DMD rises due to the heat generated by the operation of the DMD and the heat generated by the light irradiated to the reflector portion of the DMD. When the temperature of the DMD deviates from the range of the prescribed operating temperature condition, the quality of the DMD may deteriorate prematurely, so the DMD is sometimes cooled in the drawing device.

[0006] For example, in the device of the specification of Chinese Utility Model Publication No. 216671613 (Document 1), an air cooling component is provided for blowing air toward the lower surface of the DMD chip for cooling. Figure 3 As shown in FIG8 , an air flow path is provided inside the mounting base 9 supporting the DMD assembly 5 from below, and air is blown from the jet port of the air flow path located on the right side in FIG8 toward the lower surface of the DMD chip disposed in the through hole of the mounting base 9. A guide plate 11 is provided near the jet port of the air flow path, and the flow path cross-sectional area of ​​the air flow path decreases as it approaches the jet port. Therefore, the air flowing in the air flow path is ejected from the jet port while increasing speed and blown toward the lower surface of the DMD chip. The air blown to the lower surface of the DMD chip is discharged from the air flow path located on the left side in FIG8 .

[0007] However, in the device of document 1, moisture in the air condenses due to adiabatic expansion of the air ejected from the ejection port, and water droplets adhere to the glass cover surface of the DMD chip. In the above-mentioned drawing device, if water droplets adhere to the glass cover surface of the DMD chip and become dirty, the amount of light irradiated to the substrate is reduced. Summary of the invention

[0008] An object of the present invention is to suppress condensation and cool a digital micromirror device.

[0009] Mode 1 of the present invention is an optical device for irradiating modulated light to an object, wherein the device comprises: an illumination optical system into which light emitted from a light source is incident; a light modulator for modulating the light guided by the illumination optical system; and a projection optical system for guiding the light modulated by the light modulator toward the object. The light modulator comprises: a digital micromirror device; and a cooling unit for cooling the digital micromirror device. The digital micromirror device comprises: a DMD base; a DMD reflector unit comprising a plurality of movable micromirrors arranged in a matrix on one side in the thickness direction of the DMD base; and a DMD cover unit for covering the DMD reflector unit from the one side in the thickness direction. The cooling part comprises: an ejection flow path, which forms an airflow along the main surface of the one side in the thickness direction of the DMD cover by ejecting gas from a jet port, thereby cooling the digital micromirror device; and a supply flow path, which connects a gas supply source and the ejection flow path, and guides the compressed gas sent from the gas supply source to the ejection flow path, and the flow path cross-sectional area of ​​the supply flow path is smaller than the flow path cross-sectional area of ​​the ejection flow path.

[0010] According to the present invention, it is possible to suppress condensation and cool the digital micromirror device.

[0011] Mode 2 of the present invention is an optical device according to Mode 1, wherein the light modulating section further comprises a device holding section for holding the digital micromirror device. The device holding section comprises a cover accommodating recess, the cover accommodating recess is open on the one side in the thickness direction and the DMD cover section is arranged inside. The ejection flow path comprises at least a portion of a through flow path that passes through the device holding section from the inner peripheral surface of the cover accommodating recess. The connection section between the supply flow path and the ejection flow path is located at the end of the through flow path on the side opposite to the cover accommodating recess or in the middle of the through flow path.

[0012] Aspect 3 of the present invention is an optical device according to aspect 1 (or may be aspect 1 or 2), wherein the size of the ejection port in a direction perpendicular to the thickness direction is larger than the size of the ejection port in the thickness direction.

[0013] A fourth aspect of the present invention is an optical device according to aspect 1 (or any one of aspects 1 to 3), wherein a flow path cross-sectional area of ​​the discharge flow path is 2.25 times or more of a flow path cross-sectional area of ​​the supply flow path.

[0014] According to mode 5 of the present invention, in the optical device according to mode 1 (or any one of modes 1 to 4), the flow direction of the airflow formed by the cooling portion is parallel to the main surface of the one side in the thickness direction of the DMD cover portion.

[0015] According to a sixth aspect of the present invention, in the optical device of the first aspect (or any one of the first to fifth aspects), the incident direction of light on the digital micromirror device is inclined in a lateral direction perpendicular to the thickness direction relative to the thickness direction. The flow direction of the airflow formed by the cooling unit is parallel to the lateral direction.

[0016] Mode 7 of the present invention is an optical device according to Mode 1 (or any one of Modes 1 to 6), wherein the cooling unit further comprises: another ejection flow path, which forms another airflow along the main surface of the one side of the thickness direction of the DMD cover by ejecting gas from another ejection port, thereby cooling the digital micromirror device; and another supply flow path, which connects a gas supply source and the other ejection flow path, guides the compressed gas sent from the gas supply source to the other ejection flow path, and the flow path cross-sectional area of ​​the other supply flow path is smaller than the flow path cross-sectional area of ​​the other ejection flow path. The airflow caused by the gas ejected from the ejection port flows from one side in the lateral direction perpendicular to the thickness direction to the other side. The other airflow caused by the gas ejected from the other ejection port flows from the other side in the lateral direction to the one side.

[0017] According to an eighth aspect of the present invention, in the optical device of the seventh aspect, the ejection port and the other ejection ports are located at different positions from each other in a direction perpendicular to the thickness direction and the lateral direction.

[0018] Mode 9 of the present invention is a drawing device for drawing a pattern by irradiating light on a substrate, wherein the device comprises: a stage for holding the substrate; an optical device described in any one of Modes 1 to 8 for irradiating modulated light on the substrate; and a scanning mechanism for moving the stage relative to the optical device in a scanning direction parallel to the main surface of the substrate.

[0019] The above-mentioned objects and other objects, features, aspects and advantages will become clearer with reference to the accompanying drawings and the following detailed description of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a perspective view showing a drawing device according to one embodiment.

[0021] Figure 2 It is a side view depicting the head.

[0022] Figure 3 It is a side view of the light modulation unit.

[0023] Figure 4 It is a three-dimensional diagram of the light modulation unit.

[0024] Figure 5This is a bottom view of the light modulation unit.

[0025] Figure 6 It is a perspective view showing the first ejection port.

[0026] Description of Reference Numerals

[0027] 1Drawing device 6DMD (digital micromirror device)

[0028] 7Cooling section

[0029] 9 substrates

[0030] 10. Optical Device

[0031] 21 stage

[0032] 22 Stage moving mechanism

[0033] 43 Illumination optical system

[0034] 44 Light modulation unit

[0035] 45 Projection optical system

[0036] 60 Support substrate

[0037] 61DMD base unit

[0038] 62DMD reflector unit

[0039] 63DMD cover

[0040] 91 upper surface (of substrate)

[0041] 421 Light Source

[0042] 601 through hole

[0043] 602 inner peripheral surface 612 main surface (DMD base portion)

[0044] 631 Main surface (DMD cover)

[0045] 761 through flow path

[0046] 763 First Exhaust Port

[0047] 764 first ejection flow path

[0048] 765 first supply flow path

[0049] 766 connection

[0050] 771 through flow path

[0051] 773 Second Exhaust Port

[0052] 774 Second ejection flow path

[0053] 775 Second supply flow path

[0054] 776 connection DETAILED DESCRIPTION

[0055] Figure 1 1 is a perspective view showing a drawing device 1 according to an embodiment of the present invention. The drawing device 1 is a direct drawing device that irradiates a photosensitive material on a substrate 9 with a substantially light beam after spatial modulation and scans the irradiation area of ​​the light on the substrate 9 to draw a pattern. Figure 1 In FIG. 1 , three directions orthogonal to each other are indicated by arrows as the X direction, the Y direction, and the Z direction. Figure 1 In the example shown, the X direction and the Y direction are horizontal directions perpendicular to each other, and the Z direction is a vertical direction (ie, an up-and-down direction). The same is true in other figures.

[0056] The substrate 9 is, for example, a printed circuit board in a substantially rectangular flat plate shape. On the main surface (hereinafter, also referred to as "upper surface 91") on the (+Z) side of the substrate 9, a resist film formed of a photosensitive material is provided on the copper layer. In the drawing device 1, a circuit pattern is drawn (i.e., formed) on the resist film of the substrate 9. It should be noted that the type and shape of the substrate 9 can be variously changed.

[0057] The drawing device 1 is arranged in a clean room (not shown). The temperature in the clean room is, for example, 20° C. to 23° C., and the relative humidity in the clean room is, for example, 33% to 48%.

[0058] The drawing device 1 includes: a stage 21, a stage moving mechanism 22, an alignment unit 3, and a drawing unit 4. The stage 21 is a roughly rectangular flat plate-shaped member arranged on the lower side (i.e., the (-Z) side) than the alignment unit 3 and the drawing unit 4. The stage 21 has a substrate holding portion 25 that holds the substrate 9 in a horizontal state from the lower side. The substrate holding portion 25 is, for example, a vacuum chuck that absorbs and holds the lower surface of the substrate 9. The substrate holding portion 25 may have a structure other than a vacuum chuck, for example, it may be a mechanical chuck. The upper surface 91 of the substrate 9 placed on the substrate holding portion 25 is roughly perpendicular to the Z direction and roughly parallel to the X direction and the Y direction.

[0059] The stage moving mechanism 22 is a moving mechanism that moves the stage 21 relative to the alignment section 3 and the drawing section 4 in the horizontal direction (i.e., a direction roughly parallel to the upper surface 91 of the substrate 9). The stage moving mechanism 22 is installed on the upper surface of the base 11 and is supported by the base 11 from the bottom. The stage moving mechanism 22 has a first moving mechanism 23 and a second moving mechanism 24. The second moving mechanism 24 supports the stage 21 from the bottom and moves the stage 21 linearly in the X direction along the guide rail. The first moving mechanism 23 supports the second moving mechanism 24 from the bottom and moves the stage 21 linearly in the Y direction along the guide rail together with the second moving mechanism 24. The driving source of the first moving mechanism 23 and the second moving mechanism 24 is, for example, a linear servo motor or a driving source in which a motor is mounted on a ball screw. The structures of the first moving mechanism 23 and the second moving mechanism 24 can be changed in various ways.

[0060] The drawing device 1 may be provided with a stage rotating mechanism that rotates the stage 21 around a rotation axis extending in the Z direction. In addition, the drawing device 1 may be provided with a stage lifting mechanism that moves the stage 21 in the Z direction. As the stage rotating mechanism, for example, a servo motor may be used. As the stage lifting mechanism, for example, a linear servo motor may be used. The structures of the stage rotating mechanism and the stage lifting mechanism may be modified in various ways.

[0061] The alignment unit 3 has a plurality of alignment cameras 31. Figure 1 In the example shown, two alignment cameras 31 are arranged in the X direction, but only the alignment camera 31 on the (+X) side is shown. Each alignment camera 31 is supported above the stage 21 and the stage moving mechanism 22 by a support portion 27 provided across the stage 21 and the stage moving mechanism 22. The support portion 27 is, for example, a single metal member provided at one position in the Y direction. Figure 1 In the illustrated example, the support portion 27 is a door-shaped member (so-called gantry) spanning the stage 21 and the stage moving mechanism 22 , and is vertically provided on the upper surface of the base 11 .

[0062] exist Figure 1 In the example shown, two alignment cameras 31 are mounted on the side surface of the (+Y) side of the support portion 27. Of the two alignment cameras 31, for example, one alignment camera 31 is fixed to the support portion 27, and the other alignment camera 31 can be moved along the X direction on the support portion 27. Thus, the distance in the X direction between the two alignment cameras 31 can be changed. It should be noted that the number of alignment cameras 31 of the alignment portion 3 can be one, or three or more.

[0063] Each alignment camera 31 captures an alignment mark (not shown) pre-set on the upper surface 91 of the substrate 9. In the drawing device 1, the substrate 9 is aligned (i.e., the relative position of the substrate 9 with respect to the drawing head 41 is corrected) based on the image of the alignment mark acquired by the alignment camera 31.

[0064] The drawing unit 4 has a plurality of (in Figure 1 In the example shown, there are six drawing heads 41. The plurality of drawing heads 41 have substantially the same structure. Each drawing head 41 has a light modulator that irradiates modulated (i.e., spatially modulated) light downward. Each drawing head 41 is supported by the support portion 27 above the stage 21 and the stage moving mechanism 22. Figure 1 In the example shown, six drawing heads 41 are mounted on the side surface of the (-Y) side of the support portion 27. It should be noted that the alignment camera 31 may be supported by a support portion different from the support portion 27 to which the drawing heads 41 are mounted.

[0065] exist Figure 1 In the example shown, six drawing heads 41 are arranged in a substantially straight line substantially parallel to the X direction. The positions of the six drawing heads 41 in the Y direction and the Z direction are substantially the same. It should be noted that the plurality of drawing heads 41 do not necessarily need to be arranged in a straight line, and for example, they may be arranged in a staggered manner. In the case where the drawing heads 41 are arranged in a staggered manner, for example, the plurality of drawing heads 41 are arranged substantially parallel to the X direction at a first position in the Y direction, and at a second position adjacent to the (-Y) side of the first position, the drawing heads 41 are arranged between the plurality of drawing heads 41 in the X direction. In addition, in the drawing unit 4, the number of the drawing heads 41 may be one, or may be two or more.

[0066] In the drawing device 1, pattern drawing on the substrate 9 is performed in a so-called multi-path method. Specifically, modulated light is irradiated onto the upper surface 91 of the substrate 9 from the plurality of drawing heads 41 of the drawing unit 4, and the substrate 9 is moved in the Y direction and passes under the drawing heads 41 by the first moving mechanism 23 of the stage moving mechanism 22. Thus, the irradiation area of ​​the light from the plurality of drawing heads 41 is scanned on the substrate 9 in the Y direction, and the substrate 9 is drawn. Next, the substrate 9 is moved stepwise by a predetermined distance in the X direction by the second moving mechanism 24. Then, the substrate 9 is moved in the Y direction by the first moving mechanism 23 again, and light is irradiated from the drawing heads 41 to the substrate 9 in parallel with the movement, and the substrate 9 is drawn. In the drawing device 1, a pattern is drawn on the substrate 9 by alternately irradiating the substrate 9 moving in the Y direction with light and stepping the substrate 9 in the X direction.

[0067] In the following description, the Y direction is referred to as the "main scanning direction" or "scanning direction", and the X direction is referred to as the "sub-scanning direction". The main scanning direction and the sub-scanning direction are directions substantially parallel to the upper surface 91 of the substrate 9. In the stage moving mechanism 22, the first moving mechanism 23 is a main scanning mechanism that moves the stage 21 relative to the drawing head 41 in the main scanning direction. The second moving mechanism 24 is a sub-scanning mechanism that moves the stage 21 relative to the drawing head 41 in the sub-scanning direction.

[0068] It should be noted that, in the drawing device 1, the substrate 9 may be drawn in a single-path method (also referred to as a single-path method) in which the drawing of the pattern on the substrate 9 is completed by moving the substrate 9 only once relative to the drawing head 41 in the Y direction. In this case, when drawing the pattern, the sub-scanning (i.e., the stepping movement in the X direction) of the substrate 9 by the second moving mechanism 24 is not performed. That is, the stage moving mechanism 22 is a scanning mechanism that moves the stage 21 at least in the scanning direction relative to the drawing head 41.

[0069] Figure 2 This is a side view of a drawing head 41 enlarged and observed from the (+X) side. The drawing head 41 includes a light source unit 42, an illumination optical system 43, a light modulation unit 44, a projection optical system 45, and a drawing head cover 46. The light source unit 42, the illumination optical system 43, the light modulation unit 44, and the projection optical system 45 are accommodated inside the drawing head cover 46. Figure 2 In order to facilitate understanding of the drawings, the head cover 46 is shown in cross section, and the internal structure of the head cover 46 is shown by solid lines. Figure 2 The support portion 27 is also shown.

[0070] exist Figure 2 In the example shown, the drawing head cover 46 is a member that is substantially L-shaped when viewed from the side. The light source unit 42 is arranged inside the drawing head cover 46 at the end portion on the (+Y) side of the upper portion of the drawing head 41. The illumination optical system 43 is arranged inside the drawing head cover 46 at the (-Y) side of the light source unit 42 at the upper portion of the drawing head 41. The illumination optical system 43 extends substantially parallel to the Y direction. The light modulation unit 44 is arranged inside the drawing head cover 46 at the end portion on the (-Y) side of the upper portion of the drawing head 41. The light modulation unit 44 is located on the (-Y) side of the illumination optical system 43.

[0071] The projection optical system 45 is disposed inside the drawing head cover 46 at the end of the drawing head 41 on the (-Y) side, on the (-Z) side (i.e., below) of the light modulation unit 44. The projection optical system 45 extends substantially parallel to the Z direction. Figure 2In the example shown, the lower end of the drawing head cover 46 is open, and the lower end of the projection optical system 45 protrudes downward from the lower end opening of the drawing head cover 46. A focus sensor for adjusting the focus of the drawing head 41 may be provided near the lower end of the projection optical system 45.

[0072] The shape of the drawing head cover 46 may be changed in various ways. For example, the drawing head cover 46 may be a member extending substantially parallel to the Z direction. In this case, the illumination optical system 43 and the light source unit 42 are disposed on the (+Z) side of the light modulation unit 44 .

[0073] Light emitted from the light source unit 42 is incident on the illumination optical system 43 along a predetermined optical axis J1 of the drawing head 41, and is guided to the light modulation unit 44 via the illumination optical system 43 and the reflection mirrors 471, 472, etc. Figure 2 The optical axis J1 is depicted by a dot-dash line. The light modulator 44 modulates the light from the light source 42 and guides it to the projection optical system 45. The light modulated by the light modulator 44 is projected by the projection optical system 45 toward the upper surface 91 (refer to FIG. 1 ) of the object, that is, the substrate 9, which is located below the drawing head 41 (i.e., in the (-Z) direction). Figure 1 )guide.

[0074] The light source unit 42 has a light source 421 such as an LED (Light Emitting Diode) or an LD (Laser Diode). The illumination optical system 43 has optical elements such as a plurality of lenses arranged roughly parallel to the Y direction. The light modulation unit 44 has a digital micromirror device 6 (hereinafter also referred to as "DMD6") as a spatial light modulator. The projection optical system 45 has optical elements such as a plurality of lenses arranged roughly parallel to the Z direction.

[0075] It should be noted that in Figure 2 In the example shown, one light source 421 is depicted in the light source unit 42, but the number of light sources 421 provided in the light source unit 42 may be plural. For example, plural light sources 421 emitting light of different wavelengths may be provided in the light source unit 42. In this case, when drawing a pattern on the substrate 9, one or more light sources 421 among the plural light sources 421 are selected to be used in accordance with the type of photosensitive material on the substrate 9. It should be noted that the light source 421 provided in the light source unit 42 is not limited to LEDs and LDs, and various types of light sources may be used.

[0076] In the drawing device 1, the illumination optical system 43, the light modulator 44 and the projection optical system 45 constitute an optical device 10 for irradiating modulated light to an object (i.e., substrate 9). It should be noted that the optical device 10 may also include other structures such as a light source unit 42 and a drawing head cover 46.

[0077] Figure 3 It is a side view showing the light modulation unit 44 in an enlarged manner. Figure 4 It is a perspective view of the light modulation unit 44 as viewed from obliquely below. Figure 5 The bottom view of the DMD 6 of the light modulator 44 is viewed from the (-Z) side. The light modulator 44 includes the DMD 6, the support substrate 60, the cooling unit 7, and the container 8. The container 8 is a cover member provided on the (+Z) side of the support substrate 60 and covering the cooling unit 7 and the like. Figure 3 In FIG. 8 , the receiving member 8 is shown in cross section. Figure 4 The receiving member 8 is shown by dashed lines.

[0078] The support substrate 60 is a roughly flat plate-shaped member extending roughly perpendicularly to the Z direction, and is used to support the DMD 6 and the cooling unit 7. The shape of the support substrate 60 when viewed from above (i.e., the shape when viewed from the (+Z) side parallel to the Z direction) is, for example, roughly rectangular. The support substrate 60 is provided with a through hole 601 that passes through the support substrate 60 in the Z direction. The shape of the through hole 601 when viewed from above is, for example, roughly circular. Figures 3 to 5 In the example shown, the portion around the through hole 601 in the support substrate 60 is thicker in the Z direction than other portions of the support substrate 60 (eg, the end portion on the (+Y) side and the end portion on the (−Y) side).

[0079] The DMD 6 is a substantially rectangular member in a plan view. The DMD 6 is mounted from above on a through hole 601 provided on the support substrate 60. In other words, the DMD 6 is mounted on the upper surface (i.e., the main surface on the (+Z) side) of the support substrate 60 in a manner overlapping with the through hole 601 in a plan view. That is, the support substrate 60 is a device holding portion that holds the DMD 6.

[0080] The DMD 6 has a DMD base portion 61, a DMD reflector portion 62, and a DMD cover portion 63. The DMD base portion 61 is a roughly flat member extending roughly perpendicularly to the Z direction. That is, the Z direction is the thickness direction of the DMD base portion 61, and is also the thickness direction of the DMD 6. The shape of the DMD base portion 61 when viewed from above is, for example, roughly rectangular. The DMD base portion 61 is in direct or indirect contact with the upper surface of the support substrate 60 and is supported from below by the support substrate 60. The DMD base portion 61 is provided with a receiving portion for receiving a driving signal input from the outside of the DMD 6, and a driving portion for driving the DMD reflector portion 62 based on the driving signal, etc.

[0081] The DMD reflector 62 is provided on the main surface of the (-Z) side of the DMD base 61. The shape of the DMD reflector 62 when viewed from above is, for example, a substantially rectangular shape. The size of the DMD reflector 62 when viewed from above is smaller than the size of the DMD base 61 when viewed from above. The DMD reflector 62 is entirely covered by the DMD base 61 from the (+Z) side.

[0082] The DMD reflector unit 62 has a plurality of movable micro-mirrors (not shown) arranged in a matrix. The plurality of micro-mirrors are driven independently of each other by the above-mentioned driving unit arranged on the DMD base unit 61, and can switch between an on state and an off state. The plurality of micro-mirrors are arranged in a roughly planar shape at roughly the same position in the Z direction. The plurality of micro-mirrors are arranged roughly parallel in the X direction and the Y direction, for example. The DMD reflector unit 62 is arranged inside the through hole 601 of the support substrate 60. The lower surface of the DMD reflector unit 62 is located at a position lower than the upper surface of the support substrate 60 around the through hole 601 and at a position higher than the lower surface of the support substrate 60 around the through hole 601.

[0083] In the optical modulation section 44, the light guided to the DMD6 is incident on the DMD6 from the (-Z) side of the DMD6, is reflected by the DMD reflector section 62 and is guided to the (-Z) side of the DMD6. That is, the (-Z) side of the DMD6 (i.e., one side in the thickness direction) is the incident side (i.e., the front side) on which the above-mentioned light is incident, and the (+Z) side of the DMD6 (i.e., the other side in the thickness direction) is the back side located on the opposite side of the incident side of the light. The principal surface 612 on the (+Z) side of the DMD base section 61 is also the principal surface on the (+Z) side of the DMD6, and is also referred to as the "back side 612 of the DMD6" in the following description. The principal surface 612 on the (+Z) side of the DMD base section 61 is a roughly flat surface that is roughly perpendicular to the Z direction.

[0084] The DMD cover 63 is a light-transmitting member that covers the plurality of micro-mirrors of the DMD reflector 62 from below. The DMD cover 63 is, for example, a roughly rectangular or flat member with an opening on the (+Z) side. The DMD cover 63 is mounted on the main surface on the (-Z) side of the DMD base 61. The DMD cover 63 is, for example, a glass cover made of transparent quartz glass. The light incident on the DMD 6 is incident on the DMD reflector 62 through the DMD cover 63. In addition, the light reflected by the DMD reflector 62 is guided to the outside of the DMD 6 through the DMD cover 63.

[0085] The DMD cover 63 is arranged inside the through hole 601 of the support substrate 60. The main surface 631 (i.e., the lower surface) on the (-Z) side of the DMD cover 63 is located below the upper surface of the support substrate 60 around the through hole 601 and above the lower surface of the support substrate 60 around the through hole 601. The main surface 631 on the (-Z) side of the DMD cover 63 is a substantially flat surface substantially perpendicular to the Z direction. The through hole 601 of the support substrate 60 is open on the (-Z) side and is a cover accommodating recessed portion in which the cover 63 is arranged.

[0086] The cooling unit 7 is a mechanism for cooling the DMD 6. The cooling unit 7 includes a back cooling unit 71 and a front cooling unit 74. The back cooling unit 71 is located at a position overlapping with the DMD 6 in a plan view and is arranged on the (+Z) side of the DMD 6 (i.e., opposite to the DMD 6). Figure 1 The back cooling unit 71 is in contact with the main surface 612 (i.e., the upper surface) on the (+Z) side of the DMD base unit 61, and cools the DMD 6 from the DMD base unit 61 side by heat conduction. The front cooling unit 74 is arranged on the (-Z) side of the DMD 6, and forms an airflow that flows along the main surface 631 (i.e., the lower surface) on the (-Z) side of the DMD cover unit 63, and cools the DMD 6 from the DMD cover unit 63 side. The main surface 631 on the (-Z) side of the DMD cover unit 63 is also the main surface on the (-Z) side of the DMD 6, and is also referred to as the "front face 631 of the DMD" in the following description.

[0087] The back cooling part 71 is a roughly rectangular parallelepiped member having a flow path provided therein, and is a cooling jacket in which a fluid refrigerant flows in the flow path. The refrigerant is, for example, a liquid such as water. The refrigerant may also be a liquid other than water, a gas, or a two-phase fluid obtained by mixing a liquid and a gas. In the present embodiment, the back cooling part 71 is a water-cooling jacket in which water flows in the flow path.

[0088] In the back cooling portion 71, a convex portion is provided at the lower end portion, which protrudes downward (i.e., toward the back side 612 of the DMD 6) from the approximate center portion in the X direction. The lower end surface of the convex portion is indirectly in contact with the main surface 612 on the (+Z) side of the DMD base portion 61 via a sheet-like heat transfer component 711. The heat transfer component 711 is a heat sink with a relatively high thermal conductivity. It should be noted that the shape of the back cooling portion 71 can be changed in various ways. In addition, the back cooling portion 71 can also directly contact the main surface 612 on the (+Z) side of the DMD base portion 61 without passing through the heat transfer component 711 or the like.

[0089] The back cooling unit 71 is forced toward the main surface 612 (i.e., the back surface 612 of the DMD 6) on the (+Z) side of the DMD base unit 61 by the force applying unit 72 connected to the support substrate 60. Thus, the temperature rise of the DMD base unit 61 is appropriately suppressed. In other words, the cooling of the DMD 6 from the DMD base unit 61 side by the back cooling unit 71 is appropriately achieved.

[0090] It should be noted that the force applied by the back cooling unit 71 to the main surface 612 on the (+Z) side of the DMD base unit 61 (hereinafter also referred to as "back force") is set to an upper limit value based on the relationship with the structure of the DMD 6. The structure of the force applying unit 72 is selected so that the back force does not exceed the upper limit value. In addition, the thermal conductivity and thickness of the heat transfer member 711 are set so that a sufficient heat transfer effect (i.e., heat dissipation effect) can be obtained under the back force.

[0091] The storage member 8 is a cylindrical (i.e., box-shaped) member with a cover that opens downward. Figure 4 In the example shown, the outer shape of the containing member 8 is roughly rectangular, and has a top cover portion 81 and a side wall portion 82. The top cover portion 81 of the containing member 8 is a roughly flat plate-shaped portion that extends roughly perpendicularly to the Z direction. The side wall portion 82 of the containing member 8 is a roughly flat plate-shaped portion that extends downward from the outer peripheral edge of the top cover portion 81 throughout the entire circumference. The containing member 8 covers the back cooling portion 71 and the force applying portion 72, etc., and is mounted on the upper surface of the supporting substrate 60. Thus, the back cooling portion 71 and the force applying portion 72, etc. are contained in the internal space 80 of the containing member 8. It should be noted that the outer shape of the containing member 8 is not necessarily limited to a roughly rectangular shape, and may also be other shapes (for example, roughly cylindrical, roughly polygonal, or dome-shaped, etc.).

[0092] An air supply port 83 connected to a pipe extending from a dry gas supply source (not shown) is provided in the side wall portion 82 of the container member 8. Dry gas having a lower dew point than the ambient gas around the container member 8 (i.e., the space outside the container member 8) is supplied to the internal space 80 of the container member 8 through the air supply port 83. Thus, condensation on the surface of the back cooling portion 71 and the like is suppressed, and adhesion of moisture to the DMD 6 is suppressed. The dry gas supplied to the internal space 80 of the container member 8 is discharged to the outside of the container member 8 through an exhaust port (not shown) provided separately from the air supply port 83 in the side wall portion 82 of the container member 8. The above-mentioned dry gas is, for example, CDA (clean dry air). The dry gas may also be, for example, nitrogen (N 2 ) and other inert gases.

[0093] The front cooling part 74 has a first ejection part 76 and a second ejection part 77. The first ejection part 76 and the second ejection part 77 are connected to a gas supply source (not shown in the figure), and the temperature rise of the DMD cover part 63 and the DMD reflector part 62 is suppressed by supplying compressed gas to the DMD cover part 63. The gas contains, for example, water vapor in an unsaturated state. In the present embodiment, compressed air at room temperature (for example, 20°C to 23°C) is supplied from the gas supply source to the first ejection part 76 and the second ejection part 77. The pressure of the compressed air when it is sent from the gas supply source is, for example, 0.3MPaG to 0.5MPaG, and preferably 0.3MPaG to 0.4MPaG. The delivery amount of the compressed air from the gas supply source is, for example, 25L / min (liters / minute) to 45L / min, and preferably 25L / min to 35L / min. The dew point under the pressure of the compressed air is, for example, below -40°C.

[0094] The first ejection portion 76 includes a through-flow path 761, which extends from the inner peripheral surface 602 of the through hole 601 in the (-Y) direction inside the support substrate 60 on the (-Y) side of the DMD cover portion 63 and the DMD reflector portion 62, and penetrates the support substrate 60 along the Y direction. The end of the (-Y) side of the through-flow path 761 is connected to the above-mentioned gas supply source via a pipe 762. The pipe 762 is, for example, a flexible pipe with flexibility. The flow path cross-sectional area of ​​the pipe 762 (that is, the area of ​​the internal space of the pipe 762 in the cross section perpendicular to the length direction of the pipe 762) is approximately constant over the substantially entire length of the pipe 762.

[0095] The gas supplied from the gas supply source to the through-flow passage 761 via the pipe 762 is ejected from the end opening on the (+Y) side of the through-flow passage 761 located on the inner circumferential surface 602 of the through-hole 601 toward the space inside the through-hole 601 (i.e., the space surrounded by the inner circumferential surface 602 of the through-hole 601). In the following description, the end opening on the (+Y) side of the through-flow passage 761 is referred to as the "first ejection port 763".

[0096] Figure 6 FIG. 7 is a perspective view showing an enlarged view of the first ejection port 763. Figure 6 The illustrated first ejection port 763 is roughly rectangular, and its size in the circumferential direction along the inner circumferential surface 602 of the through hole 601 (i.e., the width in the X direction) is smaller than its size in the thickness direction of the DMD 6 (i.e., the height in the Z direction). The above-mentioned circumferential direction is the circumferential direction centered on the central axis of the through hole 601 extending in the Z direction (i.e., the up-down direction), and is a direction perpendicular to the Z direction. It should be noted that the shape of the first ejection port 763 is not limited to a rectangle, and various changes can be made.

[0097] like Figures 3 to 5As shown, the second ejection portion 77 includes a through-flow path 771, which extends from the inner peripheral surface 602 of the through hole 601 in the (+Y) direction inside the support substrate 60 on the (+Y) side of the DMD cover portion 63 and the DMD reflector portion 62 and penetrates the support substrate 60 in the Y direction. The end of the (+Y) side of the through-flow path 771 is connected to the above-mentioned gas supply source via a pipe 772. The pipe 772 is, for example, a flexible pipe with flexibility. The flow path cross-sectional area of ​​the pipe 772 is substantially constant within the substantially entire length of the pipe 772.

[0098] The gas supplied from the gas supply source to the through-flow passage 771 via the pipe 772 is ejected from the end opening on the (-Y) side of the through-flow passage 771 located on the inner circumferential surface 602 of the through-flow passage 771 to the space inside the through-flow passage 601. In the following description, the end opening on the (-Y) side of the through-flow passage 771 is referred to as the "second ejection port 773". The shape of the second ejection port 773 is similar to that of the second ejection port 773. Figure 6 The shapes of the first discharge ports 763 shown as examples are substantially the same.

[0099] exist Figure 5 In the example shown, the first jet outlet 763 is arranged near the end of the (-Y) side of the through hole 601, and the second jet outlet 773 is arranged near the end of the (+Y) side of the through hole 601. In other words, the first jet outlet 763 and the second jet outlet 773 are substantially opposite to each other in the Y direction across the cover portion 63 and the DMD reflector portion 62. It should be noted that the arrangement of the first jet outlet 763 and the second jet outlet 773 is not limited to the above example, and various changes can be made.

[0100] The first jet outlet 763 and the second jet outlet 773 eject gas approximately parallel to the Y direction. The flow of the gas ejected from the first jet outlet 763 (hereinafter also referred to as the "first airflow") flows approximately parallel to the Y direction from the (-Y) side to the (+Y) side along the main surface 631 on the (-Z) side of the DMD cover 63 (i.e., the front face 631 of the DMD6). The flow of the gas ejected from the second jet outlet 773 (hereinafter also referred to as the "second airflow") flows approximately parallel to the Y direction from the (+Y) side to the (-Y) side along the main surface 631 on the (-Z) side of the DMD cover 63. In the present embodiment, the first airflow and the second airflow flow approximately parallel to the main surface 631 on the (-Z) side of the DMD cover 63. The temperatures of the first airflow and the second airflow are lower than the temperatures of the DMD cover 63 and the DMD reflector 62 of the DMD6 being driven, and therefore, the DMD cover 63 and the DMD reflector 62 are appropriately cooled. In addition, the first airflow and the second airflow are formed in the space inside the through hole 601 , and the gas is difficult to diffuse into the surrounding space, so the DMD cover part 63 and the DMD mirror part 62 are cooled better.

[0101] like Figure 2 As shown, the incident direction of the light entering the DMD6 from the illumination optical system 43 via the reflectors 471 and 472 is Figure 2 In other words, the incident direction is inclined toward the (-Y) direction relative to the Z direction (i.e., the thickness direction of the DMD base 61). In other words, the incident direction is substantially parallel to the YZ plane and is inclined relative to both the Y direction and the Z direction in the YZ plane.

[0102] Therefore, when the drawing device 1 draws the substrate 9, the amount of light irradiated to the DMD mirror unit 62 is uneven in the Y direction (hereinafter also referred to as "lateral"), and the temperature distribution of the DMD mirror unit 62 in the Y direction may be uneven. Figures 3 to 5 In the front cooling section 74 of the example, as described above, the flow direction of the airflow (i.e., the first airflow and the second airflow) formed by the front cooling section 74 is roughly parallel to the Y direction, thereby being able to suppress the temperature difference of DMD6 in the Y direction caused by the above-mentioned uneven temperature distribution.

[0103] exist Figure 5 In the illustrated front cooling section 74, the positions of the first jet outlet 763 and the second jet outlet 773 in the X direction (i.e., the direction perpendicular to the lateral and thickness directions) are different. Specifically, with respect to the virtual straight line L1 passing through the center of the through hole 601 and extending in the Y direction when viewed from above, the center of the first jet outlet 763 in the X direction is slightly deviated to the (+X) side, and the center of the second jet outlet 773 in the X direction is slightly deviated to the (-X) side. As a result, the collision of the first airflow and the second airflow near the DMD cover 63 (i.e., near the main surface 631 on the (-Z) side of the DMD cover 63) is suppressed, and the cooling of the DMD cover 63 and the DMD reflector section 62 can be properly achieved.

[0104] exist Figures 3 to 5 In the example shown, the through-flow path 761 of the first ejection portion 76 has a first ejection flow path 764 and a first supply flow path 765. The first ejection flow path 764 is a flow path extending from the end of the through-flow path 761 on the (+Y) side, that is, the first ejection port 763 in the (-Y) direction, and is connected to the first supply flow path 765 at the substantially center of the through-flow path 761 in the Y direction. The first supply flow path 765 is a flow path extending from the end of the first ejection flow path 764 on the (-Y) side in the (-Y) direction, and is extended to the end of the through-flow path 761 on the (-Y) side and is connected to the above-mentioned pipe 762.

[0105] That is, the through-flow path 761 of the first ejection portion 76 is composed of the first ejection flow path 764 and the first supply flow path 765, and the first ejection flow path 764 and the first supply flow path 765 each include a portion of the through-flow path 761. In addition, the connection portion 766 between the first ejection flow path 764 and the first supply flow path 765 is located in the middle of the through-flow path 761. The connection portion 766 is a portion located at one position (i.e., one point) in the Y direction, and is not a portion that exists throughout the range of a predetermined length extending in the Y direction.

[0106] The shape of the flow path cross section of the first ejection flow path 764 is substantially the same as the shape of the first ejection port 763, and is a substantially rectangular shape in which the size in the X direction is larger than the size in the Z direction. The flow path cross section area of ​​the first ejection flow path 764 is substantially constant over the substantially entire length of the first ejection flow path 764. The flow path cross section area of ​​the first ejection flow path 764 is, for example, 7.065 mm 2 ~254.3mm 2 It should be noted that the shape of the flow path cross section of the first ejection flow path 764 refers to the shape of the first ejection flow path 764 in the cross section perpendicular to the length direction (i.e., the Y direction) of the first ejection flow path 764, and the flow path cross-sectional area of ​​the first ejection flow path 764 refers to the area of ​​the first ejection flow path 764 in the cross section perpendicular to the length direction of the first ejection flow path 764. The same applies to other flow paths.

[0107] The shape of the flow path cross section of the first supply flow path 765 is a substantially rectangular shape that is smaller than the flow path cross section of the first ejection flow path 764. For example, the size of the flow path cross section of the first supply flow path 765 in the Z direction is substantially the same as the size of the flow path cross section of the first ejection flow path 764 in the Z direction, and the size of the flow path cross section of the first supply flow path 765 in the X direction is smaller than the size of the flow path cross section of the first ejection flow path 764 in the X direction. Therefore, the flow path cross section area of ​​the first supply flow path 765 is smaller than the flow path cross section area of ​​the first ejection flow path 764. The flow path cross section area of ​​the first supply flow path 765 is substantially constant over substantially the entire length of the first supply flow path 765.

[0108] The first supply flow path 765 indirectly connects the gas supply source and the first ejection flow path 764 via the pipe 762. The first supply flow path 765 guides the compressed gas (for example, compressed air) sent from the gas supply source to the first ejection flow path 764. The first ejection flow path 764 ejects the gas flowing in from the first supply flow path 765 from the first ejection port 763 in the (+Y) direction, forming a first airflow along the main surface 631 on the (-Z) side of the DMD cover 63. Thus, the DMD 6 is cooled from the DMD cover 63 side.

[0109] In the first ejection portion 76, the flow path cross-sectional area increases sharply in the connection portion 766 between the first supply flow path 765 and the first ejection flow path 764. Therefore, the gas flowing from the first supply flow path 765 to the first ejection flow path 764 may be adiabatically expanded and cooled when passing through the connection portion 766. However, the connection portion 766 is provided in the middle of the through flow path 761, and the change in the flow path cross-sectional area of ​​the connection portion 766 is not too large. For example, the flow path cross-sectional area of ​​the first ejection flow path 764 is more than 2.25 times and less than 20.25 times the flow path cross-sectional area of ​​the first supply flow path 765. Therefore, the amount of temperature reduction of the gas passing through the connection portion 766 is not too large, and condensation will not be generated in the gas due to the temperature reduction. Alternatively, even if condensation is generated in the gas, it will be immediately vaporized in the first supply flow path 765, and liquid water (i.e., mist or water droplets, etc.) will not be substantially ejected from the first ejection port 763 toward the through hole 601.

[0110] In the first ejection portion 76, the gas ejected from the first ejection flow path 764 toward the through hole 601 may also be adiabatically expanded and cooled when passing through the first ejection port 763. However, the first ejection flow path 764 is expanded from the first supply flow path 765 in the connection portion 766, and the flow path cross-sectional area is relatively large. In addition, the pressure of the gas flowing in the first ejection flow path 764 is lower than the pressure of the gas flowing in the first supply flow path 765. Therefore, the temperature drop of the gas passing through the first ejection port 763 is not too large, and condensation will not be generated in the gas due to the temperature drop. Alternatively, even if condensation is generated in the gas, it will be vaporized immediately. Therefore, it is possible to prevent or suppress liquid water (i.e., mist or water droplets, etc.) from adhering to the main surface 631 on the (-Z) side of the DMD cover portion 63.

[0111] On the other hand, assuming that the first ejection flow path 764 is not provided in the first ejection portion 76, and the first supply flow path 765 extends to the inner peripheral surface 602 of the through hole 601, the area of ​​the end opening on the (+Y) side of the first supply flow path 765 (i.e., the ejection port corresponding to the first ejection port 763) and the flow path cross-sectional area of ​​the first supply flow path 765 near the end opening are relatively small. Therefore, the gas ejected from the first supply flow path 765 toward the through hole 601 may be adiabatically expanded when passing through the end opening and the temperature may be greatly reduced. As a result, condensation occurs in the gas due to the temperature reduction, and liquid water (i.e., mist or water droplets, etc.) may adhere to the main surface 631 on the (-Z) side of the DMD cover portion 63.

[0112] exist Figures 3 to 5In the first ejection section 76 shown, as described above, by providing the first supply flow path 765 and the first ejection flow path 764, condensation in the DMD cover section 63 can be suppressed and the DMD 6 can be cooled from the DMD cover section 63 side. From the viewpoint of appropriately suppressing condensation in the DMD cover section 63, the flow path cross-sectional area of ​​the first ejection flow path 764 is preferably 2.25 times or more of the flow path cross-sectional area of ​​the first supply flow path 765, and more preferably 4 times or more.

[0113] The structure of the second ejection part 77 is substantially the same as the above-mentioned structure of the first ejection part 76. Specifically, the through-flow path 771 of the second ejection part 77 has a second ejection flow path 774 and a second supply flow path 775. The second ejection flow path 774 is a flow path extending from the end of the through-flow path 771 on the (-Y) side, that is, the second ejection port 773 in the (+Y) direction, and is connected to the second supply flow path 775 at the substantially central portion of the through-flow path 771 in the Y direction. The second supply flow path 775 is a flow path extending from the end of the second ejection flow path 774 on the (+Y) side in the (+Y) direction, and extends to the end of the through-flow path 771 on the (+Y) side and is connected to the above-mentioned pipe 772.

[0114] That is, the through-flow path 771 of the second ejection portion 77 is composed of the second ejection flow path 774 and the second supply flow path 775, and the second ejection flow path 774 and the second supply flow path 775 each include a portion of the through-flow path 771. In addition, the connection portion 776 between the second ejection flow path 774 and the second supply flow path 775 is located in the middle of the through-flow path 771. The connection portion 776 is a portion located at one position (i.e., one point) in the Y direction, and is not a portion that exists throughout the range of a predetermined length extending in the Y direction.

[0115] The shape of the flow path cross section of the second ejection flow path 774 is substantially the same as the shape of the second ejection port 773, and is a substantially rectangular shape in which the size in the X direction is larger than the size in the Z direction. The flow path cross section area of ​​the second ejection flow path 774 is substantially constant over the substantially entire length of the second ejection flow path 774. The shape of the flow path cross section of the second supply flow path 775 is a substantially rectangular shape that is smaller than the flow path cross section of the second ejection flow path 774. For example, the size of the flow path cross section of the second supply flow path 775 in the Z direction is substantially the same as the size of the flow path cross section of the second ejection flow path 774 in the Z direction, and the size of the flow path cross section of the second supply flow path 775 in the X direction is smaller than the size of the flow path cross section of the second ejection flow path 774 in the X direction. Therefore, the flow path cross section area of ​​the second supply flow path 775 is smaller than the flow path cross section area of ​​the second ejection flow path 774. The flow path cross section area of ​​the second supply flow path 775 is substantially constant over the substantially entire length of the second supply flow path 775.

[0116] The second supply flow path 775 indirectly connects the gas supply source and the second ejection flow path 774 via the pipe 772. The second supply flow path 775 guides the compressed gas (for example, compressed air) sent from the gas supply source to the second ejection flow path 774. The second ejection flow path 774 ejects the gas flowing in from the second supply flow path 775 from the second ejection port 773 in the (-Y) direction, forming a second airflow along the main surface 631 on the (-Z) side of the DMD cover 63. Thus, the DMD 6 is cooled from the DMD cover 63 side.

[0117] In the second ejection portion 77, the flow path cross-sectional area increases sharply in the connection portion 776 between the second supply flow path 775 and the second ejection flow path 774. Therefore, the gas flowing from the second supply flow path 775 to the second ejection flow path 774 may be adiabatically expanded and cooled when passing through the connection portion 776. However, the connection portion 776 is provided in the middle of the through flow path 771, and the change in the flow path cross-sectional area in the connection portion 776 is not too large. For example, the flow path cross-sectional area of ​​the second ejection flow path 774 is not less than 2.25 times and not more than 20.25 times the flow path cross-sectional area of ​​the second supply flow path 775. Therefore, the amount of temperature reduction of the gas passing through the connection portion 776 is not too large, and condensation will not be generated in the gas due to the temperature reduction. Alternatively, even if condensation is generated in the gas, it will be immediately vaporized in the second supply flow path 775, and substantially no liquid water (i.e., mist or water droplets, etc.) will be ejected from the second ejection port 773 toward the through hole 601.

[0118] In the second ejection portion 77, the gas ejected from the second ejection flow path 774 toward the through hole 601 may also be adiabatically expanded and cooled when passing through the second ejection port 773. However, the second ejection flow path 774 is expanded from the second supply flow path 775 in the connection portion 776, and the flow path cross-sectional area is relatively large. In addition, the pressure of the gas flowing in the second ejection flow path 774 is lower than the pressure of the gas flowing in the second supply flow path 775. Therefore, the temperature drop of the gas passing through the second ejection port 773 is not too large, and condensation will not be generated in the gas due to the temperature drop. Alternatively, even if condensation is generated in the gas, it will be vaporized immediately. Therefore, it is possible to prevent or suppress liquid water (i.e., mist or water droplets, etc.) from adhering to the main surface 631 on the (-Z) side of the DMD cover portion 63.

[0119] On the other hand, assuming that the second ejection flow path 774 is not provided in the second ejection portion 77, and the second supply flow path 775 extends to the inner peripheral surface 602 of the through hole 601, the area of ​​the end opening on the (-Y) side of the second supply flow path 775 (i.e., the ejection port corresponding to the second ejection port 773) and the flow path cross-sectional area of ​​the second supply flow path 775 near the end opening become relatively small. Therefore, the gas ejected from the second supply flow path 775 toward the through hole 601 may be adiabatically expanded when passing through the end opening and the temperature may be greatly reduced. As a result, condensation occurs in the gas due to the temperature reduction, and liquid water (i.e., mist or water droplets, etc.) may adhere to the main surface 631 on the (-Z) side of the DMD cover portion 63.

[0120] exist Figures 3 to 5 In the second ejection portion 77 shown, as described above, by providing the second supply flow path 775 and the second ejection flow path 774, condensation in the DMD cover portion 63 can be suppressed and the DMD 6 can be cooled from the DMD cover portion 63 side. From the viewpoint of appropriately suppressing condensation in the DMD cover portion 63, the flow path cross-sectional area of ​​the second ejection flow path 774 is preferably 2.25 times or more of the flow path cross-sectional area of ​​the second supply flow path 775, and more preferably 4 times or more.

[0121] It should be noted that, in the above example, the first ejection flow path 764 of the first ejection portion 76 includes only a portion of the through flow path 761, but is not limited thereto. For example, in the first ejection portion 76, the through flow path 761 as a whole may also be the first ejection flow path 764. In this case, the flow path cross-sectional area of ​​the through flow path 761 (i.e., the flow path cross-sectional area of ​​the first ejection flow path 764) is substantially constant over the substantially entire length of the through flow path 761. In addition, the portion near the end of the piping 762 connected to the end on the (-Y) side of the through flow path 761 or the substantially entire piping 762 is the first supply flow path 765 with a smaller flow path cross-sectional area than the first ejection flow path 764. That is, the connection portion 766 between the first supply flow path 765 and the first ejection flow path 764 is located at the end of the through flow path 761 on the opposite side of the through hole 601. The same applies to the second discharge flow path 774 and the second supply flow path 775 of the second discharge portion 77.

[0122] In addition, in the above example, the connection portion 766 between the first ejection flow path 764 and the first supply flow path 765 in the first ejection portion 76 is a portion located at one position (i.e., one point) in the Y direction, but it is not limited thereto, and may be a portion existing within a range of a predetermined length extending in the Y direction. For example, the connection portion 766 may be a portion where the flow path cross-sectional area gradually increases or increases intermittently as it moves from the end of the (+Y) side of the first supply flow path 765 toward the (+Y) direction. In this case, the first ejection flow path 764 is indirectly connected to the first supply flow path 765 via the connection portion 766, and extends from the end of the (+Y) side of the connection portion 766 to the inner peripheral surface 602 of the through hole 601. The second ejection flow path 774, the connection portion 776, and the second supply flow path 775 of the second ejection portion 77 are also the same.

[0123] As described above, the optical device 10 for irradiating modulated light to an object (the substrate 9 in the above example) includes an illumination optical system 43, a light modulator 44, and a projection optical system 45. Light emitted from a light source 421 is incident on the illumination optical system 43. The light modulator 44 modulates the light guided by the illumination optical system 43. The projection optical system 45 guides the light modulated by the light modulator 44 to the object. The light modulator 44 includes a digital micromirror device 6 (i.e., DMD6) and a cooling unit 7 for cooling the DMD6. The DMD6 includes a DMD base 61, a DMD reflector 62, and a DMD cover 63. The DMD reflector 62 includes a plurality of movable micromirrors arranged in a matrix on one side (the (-Z) side in the above example) in the thickness direction of the DMD base 61. The DMD cover 63 covers the DMD reflector 62 from the one side in the thickness direction.

[0124] The cooling unit 7 has a jet flow path (i.e., the first jet flow path 764) and a supply flow path (i.e., the first supply flow path 765). The first jet flow path 764 forms an airflow along the main surface 631 on the one side in the thickness direction of the DMD cover 63 by jetting gas from the jet port (i.e., the first jet port 763), thereby cooling the DMD 6. The first supply flow path 765 connects the gas supply source and the first jet flow path 764, and guides the compressed gas (e.g., compressed air) sent from the gas supply source to the first jet flow path 764. The flow path cross-sectional area of ​​the first supply flow path 765 is smaller than the flow path cross-sectional area of ​​the first jet flow path 764.

[0125] Thus, as described above, condensation caused by adiabatic expansion of gas near the first ejection port 763 can be suppressed, and the DMD 6 can be cooled from the DMD cover 63 side. As a result, it is possible to suppress liquid water such as mist or water droplets (hereinafter also referred to as "water droplets, etc.") from adhering to the main surface 631 on the (-Z) side of the DMD cover 63 and obstructing the irradiation of light to the object. In addition, since the first supply flow path 765 and the piping 762 that connect the first ejection flow path 764 to the gas supply source can be made thinner (i.e., the flow path cross-sectional area is reduced), the degree of freedom of configuration of the first supply flow path 765 and the configuration (i.e., setting) of the piping 762 can be increased. As a result, the optical device 10 can be miniaturized.

[0126] As described above, the light modulation section 44 preferably further includes a device holding section (the support substrate 60 in the above example) for holding the DMD 6. The device holding section includes a cover accommodating recess (i.e., a through hole 601) that opens on the above one side (the (-Z) side in the above example) in the thickness direction. A DMD cover section 63 is arranged inside the through hole 601. The first ejection flow path 764 preferably includes at least a portion of a through flow path 761 that passes through the device holding section from the inner peripheral surface 602 of the through hole 601. In addition, the connection section 766 between the first supply flow path 765 and the first ejection flow path 764 is preferably located at the end of the through flow path 761 on the opposite side of the through hole 601 or in the middle of the through flow path 761. As a result, it is not necessary to arrange the first ejection flow path 764 having a relatively large flow path cross-sectional area around the device holding section (the support substrate 60 in the above example), and therefore, the optical device 10 can be further miniaturized.

[0127] As described above, the size of the first ejection port 763 in the direction perpendicular to the thickness direction (in the above example, the X direction) is preferably larger than the size of the first ejection port 763 in the thickness direction (in the above example, the Z direction). As a result, airflow can be formed in a wider range on the main surface 631 on the (-Z) side of the DMD cover 63. As a result, the above-mentioned condensation can be suppressed and the DMD 6 can be appropriately cooled from the DMD cover 63 side.

[0128] As described above, the flow path cross-sectional area of ​​the first discharge flow path 764 is preferably 2.25 times or more of the flow path cross-sectional area of ​​the first supply flow path 765. Thus, since the above-mentioned condensation can be appropriately suppressed, it is possible to appropriately suppress the adhesion of water droplets and the like to the main surface 631 on the (-Z) side of the DMD cover 63.

[0129] As described above, the flow direction of the above-mentioned airflow formed by the cooling section 7 (specifically, the front cooling section 74 of the cooling section 7) is preferably parallel to the main surface 631 on the one side in the thickness direction of the DMD cover section 63. As a result, the stagnation of the ambient gas near the main surface 631 on the (-Z) side of the DMD cover section 63 can be appropriately suppressed, and as a result, the DMD 6 can be appropriately cooled. In addition, even if water droplets or the like are contained in the airflow, compared with the case where the airflow is blown from the first nozzle 763 toward the main surface 631 on the (-Z) side of the DMD cover section 63, it is possible to suppress the water droplets or the like from adhering to the main surface 631 of the DMD cover section 63.

[0130] As described above, the incident direction of light to DMD6 is inclined in a lateral direction (in the above example, Y direction) perpendicular to the thickness direction (in the above example, Z direction) relative to the thickness direction. Moreover, the flow direction of the airflow formed by the cooling unit 7 is preferably parallel to the lateral direction. Thus, as described above, the lateral temperature difference in DMD6 can be suppressed.

[0131] As described above, the cooling unit 7 preferably further includes other ejection channels (i.e., the second ejection channel 774) and other supply channels (i.e., the second supply channel 775). The second ejection channel 774 ejects gas from other ejection ports (i.e., the second ejection port 773) to form other airflows along the main surface 631 of the above-mentioned one side (the (-Z) side in the above-mentioned example) of the thickness direction of the DMD cover 63, thereby cooling the DMD 6. The second supply channel 775 connects the gas supply source and the second ejection channel 774, and guides the compressed gas (e.g., compressed air) sent from the gas supply source to the second ejection channel 774. The channel cross-sectional area of ​​the second supply channel 775 is smaller than the channel cross-sectional area of ​​the second ejection channel 774. In addition, preferably, the above-mentioned airflow (i.e., the first airflow) caused by the gas ejected from the first ejection port 763 flows from one side to the other side in the lateral direction perpendicular to the thickness direction (in the above example, from the (-Y) side to the (+Y) side), and the above-mentioned other airflow (i.e., the second airflow) caused by the gas ejected from the second ejection port 773 flows from the other side to one side in the lateral direction (in the above example, from the (+Y) side to the (-Y) side). Thus, the gas from the cooling unit 7 can be uniformly supplied to substantially the entire main surface 631 on the (-Z) side of the DMD cover 63. As a result, the DMD 6 can be appropriately cooled from the DMD cover 63 side, and the lateral temperature difference in the DMD 6 can be further suppressed.

[0132] As described above, the positions of the first ejection port 763 and the second ejection port 773 in the direction perpendicular to the thickness direction and the lateral direction (in the above example, the X direction) are preferably different from each other. Thus, the collision of the first airflow and the second airflow near the DMD cover 63 can be suppressed, and thus the DMD 6 can be appropriately cooled from the DMD cover 63 side.

[0133] The drawing device 1 irradiates light onto the substrate 9 to draw a pattern. The drawing device 1 comprises: a stage 21, the optical device 10 and a scanning mechanism (the stage moving mechanism 22 in the above example). The stage 21 holds the substrate 9. The optical device 10 irradiates modulated light onto the substrate 9. The scanning mechanism moves the stage 21 relative to the optical device 10 in a scanning direction (the Y direction in the above example) parallel to the main surface (i.e., the upper surface 91) of the substrate 9. As described above, in the optical device 10, it is possible to prevent water droplets and the like from adhering to the main surface 631 on the (-Z) side of the DMD cover 63 and obstructing the irradiation of light to the object. Therefore, in the drawing device 1, it is possible to appropriately draw a pattern onto the substrate 9.

[0134] Next, referring to Table 1, the relationship between the ratio of the flow path cross-sectional area of ​​the first ejection flow path 764 to the flow path cross-sectional area of ​​the first supply flow path 765 (hereinafter also referred to as the "flow path cross-sectional area ratio") and the attachment of water droplets to the main surface 631 of the DMD cover part 63 is explained.

[0135]

Table 1

[0136]

[0137] Comparative Examples 1 to 6 and Examples 1 to 18 in Table 1 are the results of experiments conducted using an experimental device, the structure of which is substantially the same as that of the light modulator 44 except that the back cooling unit 71 and the second ejection unit 77 in the cooling unit 7 are omitted. It should be noted that in the experimental device, the shapes of the flow path cross sections of the first ejection flow path 764 and the first supply flow path 765 are substantially circular. In addition, the diameter of the flow path cross section of the first supply flow path 765 is 2 mm.

[0138] The "discharge port diameter (mm)" in Table 1 is the diameter of the first discharge port 763, which is the end opening of the first discharge flow path 764, and is the same as the diameter of the flow path cross section of the first discharge flow path 764. As described above, the "flow path cross-sectional area ratio" in Table 1 is the ratio of the flow path cross-sectional area of ​​the first discharge flow path 764 to the flow path cross-sectional area of ​​the first supply flow path 765. The "gas pressure (MPaG)" and "flow rate (L / min)" in Table 1 are the pressure of the compressed air when it is delivered from the above-mentioned gas supply source and the delivery amount of the compressed air from the gas supply source, respectively.

[0139] The "Evaluation" in Table 1 indicates the result of visually confirming the adhesion of water droplets, etc. to the main surface 631 of the DMD cover 63. The evaluation "E" (Excellent) means that the adhesion of water droplets, etc. to the DMD cover 63 is not confirmed at all. The evaluation "G" (Good) means that the adhesion of water droplets, etc. to the DMD cover 63 is confirmed, but the adhesion of water droplets, etc. is very small. The adhesion state of water droplets, etc. in the evaluation "G" is a state in which the amount of light reflected from the DMD can be maintained above the expected value even if the above-mentioned optical device 10 is operated for more than the prescribed service life under the same conditions as the experiment. The evaluation "P" (Poor) means that the adhesion of water droplets, etc. to the DMD cover 63 is confirmed in a relatively wide range. The adhesion state of water droplets, etc. in the evaluation "P" is a state in which it is predicted that the amount of light reflected from the DMD will become smaller than the expected value earlier than the prescribed service life when the above-mentioned optical device 10 is operated under the same conditions as the experiment.

[0140] In Comparative Examples 1 to 6, the nozzle diameter is 2 mm and the flow path cross-sectional area ratio is 1. In Comparative Examples 1 to 3, the gas pressure is 0.4 MPaG, and in Comparative Examples 4 to 6, the gas pressure is 0.5 MPaG. The flow rates of Comparative Examples 1 to 3 are 25 L / min, 35 L / min, and 45 L / min, respectively. The flow rates of Comparative Examples 4 to 6 are 25 L / min, 35 L / min, and 45 L / min, respectively.

[0141] The evaluation of Comparative Examples 1 to 6 is "P". In Comparative Examples 1 to 6, since the flow path cross-sectional area ratio is 1 (i.e., the flow path cross-sectional area of ​​the first ejection flow path 764 is the same as the flow path cross-sectional area of ​​the first supply flow path 765), as described above, the compressed air ejected from the first ejection port 763 is greatly cooled due to adiabatic expansion, etc., and water droplets, etc., adhere to the DMD cover portion 63 over a wide range.

[0142] In Examples 1 to 6, the nozzle diameter is 3 mm and the flow path cross-sectional area ratio is 2.25. In Examples 1 to 3, the gas pressure is 0.4 MPaG, and in Examples 4 to 6, the gas pressure is 0.5 MPaG. The flow rates of Examples 1 to 3 are 25 L / min, 35 L / min, and 45 L / min, respectively.

[0143] The flow rates of Examples 4 to 6 were 25 L / min, 35 L / min, and 45 L / min, respectively.

[0144] The evaluation of Examples 1 to 6 is "E" or "G". In Examples 1 to 6, since the flow path cross-sectional area of ​​the first discharge flow path 764 is larger than the flow path cross-sectional area of ​​the first supply flow path 765, as described above, the cooling of the compressed air ejected from the first ejection port 763 is suppressed, and water droplets and the like are prevented or suppressed from adhering to the DMD cover portion 63.

[0145] In Examples 7 to 12, the nozzle diameter is 4 mm and the flow path cross-sectional area ratio is 4. In Examples 7 to 9, the gas pressure is 0.4 MPaG, and in Examples 10 to 12, the gas pressure is 0.5 MPaG. The flow rates of Examples 7 to 9 are 25 L / min, 35 L / min, and 45 L / min, respectively. The flow rates of Examples 10 to 12 are 25 L / min, 35 L / min, and 45 L / min, respectively.

[0146] The evaluation of Examples 7 to 12 is "E" or "G". In Examples 7 to 12, since the flow path cross-sectional area of ​​the first discharge flow path 764 is larger than the flow path cross-sectional area of ​​the first supply flow path 765, as described above, the cooling of the compressed air ejected from the first ejection port 763 is suppressed, and water droplets and the like are prevented or suppressed from adhering to the DMD cover portion 63.

[0147] In Examples 13 to 18, the nozzle diameter is 9 mm and the flow path cross-sectional area ratio is 20.25. In Examples 13 to 15, the gas pressure is 0.4 MPaG, and in Examples 16 to 18, the gas pressure is 0.5 MPaG. The flow rates of Examples 13 to 15 are 25 L / min, 35 L / min, and 45 L / min, respectively. The flow rates of Examples 16 to 18 are 25 L / min, 35 L / min, and 45 L / min, respectively.

[0148] The evaluation of Examples 13 to 18 is "E". In Examples 13 to 18, since the flow path cross-sectional area of ​​the first discharge flow path 764 is larger than the flow path cross-sectional area of ​​the first supply flow path 765, as described above, the cooling of the compressed air ejected from the first ejection port 763 is suppressed, and water droplets and the like are prevented from adhering to the DMD cover 63.

[0149] Various modifications can be made to the above-described optical device 10 and image drawing device 1 .

[0150] For example, the first airflow formed by the gas ejected from the first ejection port 763 may flow along the (-Z) side principal surface 631 of the DMD cover 63, and does not necessarily need to flow parallel to the principal surface 631. The same is true for the second airflow formed by the gas ejected from the second ejection port 773.

[0151] In the first ejection portion 76, the flow path cross-sectional area of ​​the first ejection flow path 764 may be smaller than 2.25 times the flow path cross-sectional area of ​​the first supply flow path 765. Similarly, in the second ejection portion 77, the flow path cross-sectional area of ​​the second ejection flow path 774 may be smaller than 2.25 times the flow path cross-sectional area of ​​the second supply flow path 775.

[0152] In the first ejection portion 76, the flow path cross-sectional area of ​​the first ejection flow path 764 and the flow path cross-sectional area of ​​the first supply flow path 765 do not necessarily need to be constant over the entire length in the longitudinal direction, and may also vary over a portion of the longitudinal direction. In this case, when calculating the ratio of the flow path cross-sectional area of ​​the first ejection flow path 764 to the flow path cross-sectional area of ​​the first supply flow path 765, the representative flow path cross-sectional area of ​​each of the first ejection flow path 764 and the first supply flow path 765 is used. The representative flow path cross-sectional area of ​​the first ejection flow path 764 is the flow path cross-sectional area of ​​the first ejection flow path 764 in the first ejection port 763 (i.e., the opening area of ​​the first ejection port 763). The representative flow path cross-sectional area of ​​the first supply flow path 765 is the flow path cross-sectional area at the boundary with the connection portion 766 in the first supply flow path 765. The second ejection portion 77 is the same.

[0153] The first ejection portion 76 may also be provided with a nozzle protruding from the end of the through hole 601 side of the through flow path 761 to the (+Y) side. In this case, the nozzle is included in the first ejection flow path 764, and the end of the nozzle on the (+Y) side becomes the first ejection port 763. In addition, when the nozzle is provided, the first ejection flow path 764 may be constituted by only the nozzle, and the through flow path 761 as a whole may be the first supply flow path 765 having a smaller flow path cross-sectional area than the first ejection flow path 764. The second ejection portion 77 is substantially the same.

[0154] In the first ejection unit 76 , the first ejection flow path 764 and the first supply flow path 765 do not necessarily have to include a through flow path penetrating the support substrate 60 , and may be, for example, a flexible pipe disposed around the support substrate 60 . The same applies to the second ejection unit 77 .

[0155] In the front cooling section 74, the positions of the first and second ejection ports 763 and 773 are not limited to the above-mentioned examples, and various changes may be made. For example, the center of the first ejection port 763 in the X direction and / or the center of the second ejection port 773 in the X direction may be arranged on the above-mentioned virtual straight line L1 (see Figure 5 ). In addition, for example, the first ejection port 763 may be disposed near the end of the through hole 601 on the (+X) side, and the second ejection port 773 may be disposed near the end of the through hole 601 on the (-X) side.

[0156] As described above, the shape of the first ejection port 763 can be changed in various ways. For example, the height of the first ejection port 763 in the Z direction can be substantially the same as the width in the X direction, or can be greater than the width. In addition, for example, the shape of the first ejection port 763 viewed parallel to the Y direction can also be substantially circular or substantially oblong. The shape of the second ejection port 773 is also the same.

[0157] In addition, in the front cooling unit 74, one of the first and second ejection ports 763 and 773 may be omitted. Alternatively, in addition to the first and second ejection ports 763 and 773, another ejection port may be provided.

[0158] In the optical device 10, the shape, structure, type, etc. of the back cooling unit 71 can be changed in various ways. For example, the shape of the back cooling unit 71 can be roughly cylindrical or roughly polygonal, or roughly flat. The back cooling unit 71 is not necessarily a water cooling jacket, but can also be a Peltier element, etc. In the optical device 10, the back cooling unit 71 can also be omitted.

[0159] In the drawing device 1, the stage 21 only needs to be moved in the main scanning direction relative to the drawing head 41 by the first moving mechanism 23. Therefore, for example, the stage 21 may be fixed, and the drawing head 41 may be moved in the main scanning direction by the first moving mechanism 23 above the stage 21. Similarly, the drawing head 41 may be moved in the sub-scanning direction by the second moving mechanism 24.

[0160] The substrate 9 is not necessarily limited to a printed substrate. In the drawing device 1, for example, patterns can be drawn on semiconductor substrates, semiconductor packaging substrates, glass substrates for flat panel displays such as liquid crystal display devices or plasma display devices, glass substrates for photomasks, and substrates for solar cell panels.

[0161] The optical device 10 may be used as a device for irradiating modulated light onto the substrate 9 in a drawing device having a different structure from the drawing device 1. Alternatively, the optical device 10 may be used as a device other than a drawing device for irradiating modulated light onto an object.

[0162] The above-mentioned embodiments and the structures in the various modifications can be appropriately combined as long as they do not contradict each other.

[0163] Although the invention has been described in detail, the above description is illustrative and not restrictive, and therefore, it can be understood that many modifications and aspects can be made without departing from the scope of the invention.

Claims

1. An optical device for irradiating a modulated light onto an object, wherein: have: an illumination optical system into which light emitted from a light source is incident; a light modulation unit that modulates the light guided by the illumination optical system; as well as a projection optical system that guides the light modulated by the light modulating unit toward an object; The light modulation unit has: Digital micromirror device; and A cooling unit, for cooling the digital micromirror device; The digital micromirror device has: A digital micromirror device base portion; A digital micromirror device reflector portion, comprising a plurality of movable micromirrors arranged in a matrix on one side in the thickness direction of the digital micromirror device base portion; as well as A digital micromirror device cover portion, covering the digital micromirror device reflector portion from the one side in the thickness direction; The cooling unit has: an ejection flow path for forming an airflow along the main surface of the one side in the thickness direction of the cover of the digital micromirror device by ejecting gas from an ejection port, thereby cooling the digital micromirror device; and The supply flow path connects a gas supply source and the ejection flow path, guides the compressed gas sent from the gas supply source to the ejection flow path, and has a flow path cross-sectional area smaller than that of the ejection flow path.

2. The optical device according to claim 1, wherein: The light modulation unit further includes a device holding unit for holding the digital micromirror device. The device holding portion has a cover accommodating recessed portion, the cover accommodating recessed portion is open at the one side in the thickness direction and the digital micromirror device cover portion is arranged inside. The discharge flow path includes at least a portion of a through flow path that penetrates the device holding portion from the inner peripheral surface of the cover accommodating recessed portion. The connection portion between the supply flow path and the discharge flow path is located at an end portion of the through flow path on the opposite side to the cover accommodating recessed portion or in the middle of the through flow path.

3. The optical device according to claim 1, wherein: The size of the ejection port in a direction perpendicular to the thickness direction is larger than the size of the ejection port in the thickness direction.

4. The optical device according to claim 1, wherein: A flow path cross-sectional area of ​​the discharge flow path is 2.25 times or more of a flow path cross-sectional area of ​​the supply flow path.

5. The optical device according to claim 1, wherein: A flow direction of the airflow formed by the cooling portion is parallel to the main surface on the one side in the thickness direction of the DMD cover portion.

6. The optical device according to claim 1, wherein: The incident direction of light on the digital micromirror device is inclined in a lateral direction perpendicular to the thickness direction relative to the thickness direction. A flow direction of the airflow formed by the cooling portion is parallel to the lateral direction.

7. The optical device according to claim 1, wherein: The cooling unit also has: Another ejection flow path, by ejecting gas from another ejection port to form another airflow along the main surface of the one side in the thickness direction of the digital micromirror device cover, thereby cooling the digital micromirror device; and Another supply flow path connects the gas supply source and the other ejection flow path, guides the compressed gas sent from the gas supply source to the other ejection flow path, and the flow path cross-sectional area of ​​the other supply flow path is smaller than the flow path cross-sectional area of ​​the other ejection flow path; The gas jetted from the jet port causes the gas flow to flow from one side to the other side in a lateral direction perpendicular to the thickness direction. The other airflow caused by the gas ejected from the other ejection port flows from the other side in the lateral direction to the one side.

8. The optical device according to claim 7, wherein: The ejection port and the other ejection ports are located at different positions from each other in a direction perpendicular to the thickness direction and the lateral direction.

9. A drawing device for drawing a pattern by irradiating light onto a substrate, wherein: have: a stage, holding the substrate; The optical device according to any one of claims 1 to 8, wherein the substrate is irradiated with modulated light; and The scanning mechanism moves the stage relative to the optical device in a scanning direction parallel to the main surface of the substrate.

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