Optical device and drawing device

Abstract

To cool a DMD while simplifying the structure of a cooling part for cooling the DMD.SOLUTION: A DMD 6 includes a DMD base part 61, a DMD mirror part, and a DMD cover part 63. The DMD mirror part includes a plurality of movable micro mirrors arranged in a matrix shape on the (- Z) side of the DMD base part 61; the DMD cover part 63 covers the DMD mirror part 62 from one side in the thickness direction; a cooling part 7 includes a rear surface cooling part 71 and an energization part 72; the rear surface cooling part 71 contacts the principal surface of the DMD base part 61 on the (+Z) side and cools the DMD 6 by heat conduction; the energization part 72 contacts the rear surface cooling part 71 from the (+Z) side; the energization part 72 energizes the rear surface cooling part 71 to the principal surface of the DMD base part 61 on the (+Z) side by connecting with a support substrate 60; and this can cool the DMD 6 while simplifying the structure of the rear surface cooling part 71.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an optical device that irradiates an object with modulated light, and a drawing apparatus that includes the optical device and irradiates a substrate with light to draw a pattern. [Background technology]

[0002] Conventionally, when drawing a pattern on a printed circuit board, a semiconductor board, or the like (hereinafter referred to as a "board"), a drawing device has been used that directly draws a pattern by irradiating a photosensitive material formed on the board with modulated light and scanning the irradiated area of ​​the light.

[0003] In such a drawing device, a digital micromirror device (DMD) is used as one of the optical modulators that modulates 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 heat generated by the operation of the DMD and heat from light irradiated onto the mirror part of the DMD. If the temperature of the DMD falls outside the range of a predetermined operating temperature condition, the quality of the DMD may deteriorate early, and therefore the DMD may be cooled in the drawing device. For example, in the device of Patent Document 1, as shown in FIG. 3, the DMD is cooled by abutting a water-cooled block 2 on the side of the DMD chip opposite the mirror part in the DMD assembly 5. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] China Utility Model Publication No. 216671613 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in the device of Patent Document 1, a flange portion is provided that extends outward from the main body of the water-cooled block 2, and a through hole for screw fastening is provided in the flange portion. The flange portion is screwed to an adapter plate 4 interposed between the DMD assembly 5 and the water-cooled block 2 by a screw inserted into the through hole. Also, in this device, a spring into which the screw is inserted is provided, and the spring biases the water-cooled block 2 against the adapter plate 4. This allows the cooling block 2 to be suitably brought into contact with the DMD assembly 5 via the adapter plate 4, but the structure of the cooling block 2 becomes complicated, and the difficulty of manufacturing an optical device including a DMD increases.

[0006] The present invention has been made in consideration of the above-mentioned problems, and has an object to cool a digital micromirror device while simplifying the structure of a cooling section that cools the digital micromirror device. [Means for solving the problem]

[0007] A first aspect of the present invention is an optical device that irradiates an object with modulated light, comprising an illumination optical system into which light emitted from a light source is incident, an optical modulation section that modulates the light guided by the illumination optical system, and a projection optical system that guides the light modulated by the optical modulation section to the object. The optical modulation section comprises a digital micromirror device, a support substrate having a through hole to which the digital micromirror device is attached, and a cooling section that cools the digital micromirror device. The digital micromirror device comprises a DMD base section, a DMD mirror section including a plurality of movable micromirrors arranged in a matrix on one side in the thickness direction of the DMD base section, and a DMD cover section that covers the DMD mirror section from the one side in the thickness direction. The cooling section comprises a back surface cooling section that contacts the main surface on the other side of the thickness direction of the DMD base section and cools the digital micromirror device by thermal conduction, and a biasing section that contacts the back surface cooling section from the other side in the thickness direction and is connected to the supporting substrate to bias the back surface cooling section against the main surface on the other side in the thickness direction of the DMD base section.

[0008] A second aspect of the present invention is the optical device of the first aspect, wherein the biasing portion is indirectly connected to the support substrate by being connected to an intervening member protruding from the support substrate to the other side in the thickness direction, and a portion where the biasing portion and the intervening member are connected is located on the other side of the end of the back surface cooling portion in the thickness direction.

[0009] A third aspect of the present invention is the optical device of the first aspect (which may be either the first or second aspect), in which the biasing portion is indirectly connected to the support substrate by being connected to an intervening member protruding from the support substrate to the other side in the thickness direction. The intervening member includes a pair of support portions that extend in the thickness direction along side surfaces of the back surface cooling portion and support the back surface cooling portion by sandwiching it therebetween. The biasing portion is connected to the other end of the pair of support portions in the thickness direction.

[0010] A fourth aspect of the present invention is the optical device of the first aspect (which may be any one of the first to third aspects), in which the biasing portion is indirectly connected to the supporting substrate by being connected to an intervening member protruding from the supporting substrate to the other side in the thickness direction. The intervening member has a gate-shaped protruding portion protruding from the supporting substrate to the other side in the thickness direction and opening toward the supporting substrate. The biasing portion is connected to the other end of the protruding portion in the thickness direction.

[0011] A fifth aspect of the present invention is the optical device of the first aspect (which may be any one of the first to fourth aspects), wherein the back surface cooling section and the biasing section each have a rectangular shape in a plan view parallel to the thickness direction. In the plan view, a pair of long sides of the biasing section are perpendicular to a pair of long sides of the back surface cooling section. The biasing section is connected to the support substrate at both ends in a direction parallel to the pair of long sides of the biasing section.

[0012] A sixth aspect of the present invention is an optical device according to the first aspect (which may be any one of the first to fifth aspects), wherein the optical modulation section is arranged on the other side of the support substrate in the thickness direction, covers the back surface cooling section and is housed in an internal space, and further includes a lidded cylindrical housing member through which dry gas is supplied to the internal space.

[0013] A seventh aspect of the present invention is an optical device of aspect 1 (which may be any one of aspects 1 to 6), wherein the cooling section further includes a front cooling section that forms an airflow along the main surface on one side of the thickness direction of the DMD cover section to cool the digital micromirror device.

[0014] Aspect eight of the present invention is the optical device of aspect seven, wherein the flow direction of the airflow formed by the front surface cooling section is parallel to the main surface on the one side in the thickness direction of the DMD cover section.

[0015] A ninth aspect of the present invention is the optical device of the seventh aspect (which may be either the seventh or eighth aspect), in which the incident direction of light on the digital micromirror device is inclined in a lateral direction perpendicular to the thickness direction with respect to the thickness direction, and the flow direction of the airflow formed by the front cooling unit is parallel to the lateral direction.

[0016] Aspect 10 of the present invention is an optical device of aspect 7 (which may be any one of aspects 7 to 9), wherein the air flow formed by the front surface cooling portion includes a first air flow flowing from one side to the other side in a horizontal direction perpendicular to the thickness direction, and a second air flow flowing from the other side to the one side in the horizontal direction.

[0017] An eleventh aspect of the present invention is an optical device of an tenth aspect, wherein in a direction perpendicular to the thickness direction and the lateral direction, the position of the first nozzle forming the first air flow and the position of the second nozzle forming the second air flow are different from each other.

[0018] A twelfth aspect of the present invention is a drawing apparatus that draws a pattern by irradiating light onto a substrate, and includes a stage that holds the substrate, an optical device of any one of aspects 1 to 11 that irradiates modulated light onto the substrate, and a scanning mechanism that moves the stage relative to the optical device in a scanning direction parallel to the main surface of the substrate. Effect of the Invention

[0019] In the present invention, it is possible to cool the digital micromirror device while simplifying the structure of the rear surface cooling section. [Brief description of the drawings]

[0020] [Figure 1] 1 is a perspective view showing a drawing device according to an embodiment; [Diagram 2] FIG. [Diagram 3] FIG. 4 is a side view of the optical modulation unit. [Figure 4] FIG. [Diagram 5]FIG. 2 is a perspective view of a light modulation unit. [Figure 6] FIG. 4 is a bottom view of the optical modulation unit. [Figure 7] FIG. 13 is a side view of another optical modulation unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] FIG. 1 is a perspective view showing a drawing apparatus 1 according to one embodiment of the present invention. The drawing apparatus 1 is a direct drawing apparatus that draws a pattern by irradiating a photosensitive material on a substrate 9 with spatially modulated light in a substantially beam shape and scanning the irradiated area of ​​the light on the substrate 9. In FIG. 1, three mutually orthogonal directions are indicated by arrows as the X direction, the Y direction, and the Z direction. In the example shown in FIG. 1, the X direction and the Y direction are horizontal directions perpendicular to each other, and the Z direction is a vertical direction (i.e., an up-down direction). The same applies to other figures.

[0022] The substrate 9 is, for example, a printed circuit board having a substantially rectangular flat plate shape. On the (+Z) main surface (hereinafter also referred to as "upper surface 91") of the substrate 9, a resist film formed of a photosensitive material is provided on a copper layer. In the drawing device 1, a circuit pattern is drawn (i.e., formed) on the resist film of the substrate 9. The type, shape, etc. of the substrate 9 may be changed in various ways.

[0023] The drawing apparatus 1 includes a stage 21, a stage moving mechanism 22, an alignment unit 3, and a drawing unit 4. The stage 21 is a substantially rectangular flat member disposed below the alignment unit 3 and the drawing unit 4 (i.e., on the (-Z) side). The stage 21 includes a substrate holding unit 25 that holds the substrate 9 in a horizontal state from below. The substrate holding unit 25 is, for example, a vacuum chuck that adsorbs and holds the lower surface of the substrate 9. The substrate holding unit 25 may have a structure other than a vacuum chuck, and may be, for example, a mechanical chuck. The upper surface 91 of the substrate 9 placed on the substrate holding unit 25 is substantially perpendicular to the Z direction and substantially parallel to the X direction and the Y direction.

[0024] The stage moving mechanism 22 is a moving mechanism that moves the stage 21 relatively to the alignment unit 3 and the drawing unit 4 in a horizontal direction (i.e., a direction approximately parallel to the upper surface 91 of the substrate 9). The stage moving mechanism 22 is attached on the upper surface of the base 11 and is supported from below by the base 11. The stage moving mechanism 22 includes a first moving mechanism 23 and a second moving mechanism 24. The second moving mechanism 24 supports the stage 21 from below and linearly moves the stage 21 in the X direction along the guide rail. The first moving mechanism 23 supports the second moving mechanism 24 from below and linearly moves the stage 21 together with the second moving mechanism 24 in the Y direction along the guide rail. The driving sources of the first moving mechanism 23 and the second moving mechanism 24 are, for example, linear servo motors or motors attached to ball screws. The structures of the first moving mechanism 23 and the second moving mechanism 24 may be variously modified.

[0025] The drawing apparatus 1 may be provided with a stage rotation mechanism that rotates the stage 21 about a rotation axis extending in the Z direction. The drawing apparatus 1 may also be provided with a stage lifting mechanism that moves the stage 21 in the Z direction. For example, a servo motor can be used as the stage rotation mechanism. For example, a linear servo motor can be used as the stage lifting mechanism. The structures of the stage rotation mechanism and the stage lifting mechanism may be modified in various ways.

[0026] The alignment unit 3 includes a plurality of alignment cameras 31. In the example shown in FIG. 1, 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 movement mechanism 22 by a support 27 that is provided across the stage 21 and the stage movement mechanism 22. The support 27 is, for example, a single metal member provided at one position in the Y direction. In the example shown in FIG. 1, the support 27 is a gate-shaped member (a so-called gantry) that is provided across the stage 21 and the stage movement mechanism 22, and is erected on the upper surface of the base 11.

[0027] 1, the two alignment cameras 31 are attached to the (+Y) side surface of the support unit 27. Of the two alignment cameras 31, for example, one alignment camera 31 is fixed to the support unit 27, and the other alignment camera 31 is movable in the X direction on the support unit 27. This makes it possible to change the distance in the X direction between the two alignment cameras 31. Note that the number of alignment cameras 31 in the alignment unit 3 may be one, or three or more.

[0028] Each alignment camera 31 captures an image of an alignment mark (not shown) provided in advance on the upper surface 91 of the substrate 9. In the drawing device 1, alignment of the substrate 9 (i.e., correction of the relative position of the substrate 9 with respect to the drawing head 41) is performed based on the image of the alignment mark acquired by the alignment camera 31.

[0029] The drawing unit 4 includes a plurality of drawing heads 41 (six in the example shown in FIG. 1) arranged in the X direction. The plurality of drawing heads 41 have approximately the same structure. Each drawing head 41 includes an optical modulator that irradiates modulated (i.e., spatially modulated) light downward. Each drawing head 41 is supported above the stage 21 and the stage moving mechanism 22 by the above-mentioned support unit 27. In the example shown in FIG. 1, the six drawing heads 41 are attached to the (-Y) side surface of the support unit 27. Note that the above-mentioned alignment camera 31 may be supported by a support unit different from the support unit 27 to which the drawing heads 41 are attached.

[0030] In the example shown in FIG. 1, the six drawing heads 41 are arranged in a substantially straight line substantially parallel to the X direction. The positions of the six drawing heads 41 in the Y direction and the Z direction are substantially the same. The multiple drawing heads 41 do not necessarily need to be arranged in a straight line, and may be arranged, for example, in a staggered manner. When the drawing heads 41 are arranged in a staggered manner, for example, the multiple 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, a drawing head 41 is arranged between each of the multiple drawing heads 41 in the X direction. Moreover, the number of drawing heads 41 in the drawing unit 4 may be one or more than two.

[0031] In the drawing device 1, pattern drawing on the substrate 9 is performed by a so-called multi-pass method. Specifically, while modulated light from the multiple drawing heads 41 of the drawing unit 4 is irradiated onto the upper surface 91 of the substrate 9, the first moving mechanism 23 of the stage moving mechanism 22 moves the substrate 9 in the Y direction to pass under the drawing heads 41. As a result, the irradiation area of ​​the light from the multiple drawing heads 41 is scanned in the Y direction on the substrate 9, and drawing on the substrate 9 is performed. Next, the second moving mechanism 24 moves the substrate 9 stepwise by a predetermined distance in the X direction. Then, the first moving mechanism 23 moves the substrate 9 in the Y direction, and the drawing heads 41 irradiate the substrate 9 with light in parallel with the movement again, thereby performing drawing on the substrate 9. In the drawing device 1, the irradiation of light on the substrate 9 moving in the Y direction and the step movement of the substrate 9 in the X direction are alternately performed, thereby performing drawing on the substrate 9.

[0032] In the following description, the Y direction is also referred to as the "main scanning direction" or "scanning direction", and the X direction is also referred to as the "sub-scanning direction" or "width direction". The main scanning direction and the sub-scanning direction are directions that are approximately parallel to the upper surface 91 of the substrate 9. In the stage movement mechanism 22, the first movement mechanism 23 is a main scanning mechanism that moves the stage 21 relatively to the drawing head 41 in the main scanning direction. The second movement mechanism 24 is a sub-scanning mechanism that moves the stage 21 relatively to the drawing head 41 in the sub-scanning direction.

[0033] In the drawing apparatus 1, drawing on the substrate 9 may be performed by a single pass method (also called a one-pass method) in which drawing of a pattern on the substrate 9 is completed by moving the substrate 9 relatively to the drawing head 41 only once in the Y direction. In this case, sub-scanning of the substrate 9 by the second moving mechanism 24 (i.e., step movement in the X direction) is not performed when drawing the pattern. In other words, 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.

[0034] 2 is an enlarged side view of one drawing head 41 viewed 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 housed inside the drawing head cover 46. In FIG. 2, in order to facilitate understanding of the drawing, the drawing head cover 46 is shown in cross section, and the internal structure of the drawing head cover 46 is shown by solid lines. In addition, FIG. 2 also shows the support unit 27.

[0035] In the example shown in FIG. 2, the drawing head cover 46 is a substantially L-shaped member in a side view. The light source unit 42 is disposed inside the drawing head cover 46 at the (+Y) end of the upper part of the drawing head 41. The illumination optical system 43 is disposed inside the drawing head cover 46 at the (-Y) side of the light source unit 42 at the upper part of the drawing head 41. The illumination optical system 43 extends substantially parallel to the Y direction. The light modulation unit 44 is disposed inside the drawing head cover 46 at the (-Y) end of the upper part of the drawing head 41. The light modulation unit 44 is located on the (-Y) side of the illumination optical system 43.

[0036] The projection optical system 45 is disposed inside the drawing head cover 46 at the end on the (-Y) side of the drawing head 41, on the (-Z) side (i.e., below) of the light modulation unit 44. The projection optical system 45 extends approximately parallel to the Z direction. In the example shown in Fig. 2, 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 or the like used for focus adjustment of the drawing head 41 may be provided near the lower end of the projection optical system 45.

[0037] The shape of the drawing head cover 46 may be changed in various ways, and for example, the drawing head cover 46 may be a member extending approximately 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, for example.

[0038] The light emitted from the light source unit 42 enters 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 mirrors 471, 472, etc. In FIG. 2, the optical axis J1 is depicted by a dashed line. The light modulation unit 44 guides the light from the light source unit 42 to the projection optical system 45 while modulating it. The light modulated by the light modulation unit 44 is guided by the projection optical system 45 to the upper surface 91 (see FIG. 1) of the substrate 9, which is an object located below the drawing head 41 (i.e., in the (-Z) direction).

[0039] The light source unit 42 includes a light source 421 such as an LED (Light Emitting Diode) or an LD (Laser Diode). The illumination optical system 43 includes optical elements such as a plurality of lenses arranged substantially parallel to the Y direction. The light modulation unit 44 includes a digital micromirror device 6 (hereinafter also referred to as "DMD6") which is a spatial light modulator. The projection optical system 45 includes optical elements such as a plurality of lenses arranged substantially parallel to the Z direction.

[0040] 2, one light source 421 is depicted in the light source section 42, but the number of light sources 421 provided in the light source section 42 may be multiple. For example, multiple light sources 421 emitting light of different wavelengths may be provided in the light source section 42. In this case, when drawing a pattern on the substrate 9, one or more light sources 421 are selected and used from the multiple light sources 421 according to the type of photosensitive material on the substrate 9, etc. The light source 421 provided in the light source section 42 is not limited to an LED and an LD, and various types of light sources can be used.

[0041] In the drawing apparatus 1, the above-mentioned illumination optical system 43, light modulation unit 44, and projection optical system 45 constitute an optical device 10 that irradiates an object (i.e., substrate 9) with modulated light. Note that the optical device 10 may also include other components such as a light source unit 42 and a drawing head cover 46.

[0042] FIG. 3 is an enlarged side view of the light modulation section 44. FIG. 4 is a perspective view of the light modulation section 44 seen obliquely from above. FIG. 5 is a perspective view of the light modulation section 44 seen obliquely from below. The light modulation section 44 includes the above-mentioned DMD 6, a support substrate 60, a cooling section 7, and a housing member 8. The housing member 8 is a cover member provided on the (+Z) side of the support substrate 60 and covers the cooling section 7 and the like. To facilitate understanding of the figures, FIG. 3 shows the housing member 8 in cross section, and FIG. 4 and FIG. 5 show the housing member 8 by dashed lines.

[0043] The support substrate 60 is a substantially flat plate-like member extending substantially perpendicularly to the Z direction, and supports the DMD 6 and the cooling unit 7. The shape of the support substrate 60 in a plan view (i.e., the shape when viewed parallel to the Z direction from the (+Z) side) is, for example, substantially rectangular. The support substrate 60 is provided with a through hole 601 penetrating the support substrate 60 in the Z direction. The shape of the through hole 601 in a plan view is, for example, substantially circular. In the example shown in FIGS. 3 to 5, the portion of the support substrate 60 surrounding the through hole 601 has a greater thickness in the Z direction than other portions of the support substrate 60 (for example, the end on the (+Y) side and the end on the (-Y) side, etc.).

[0044] The DMD 6 is a member having a substantially rectangular shape in a plan view. The DMD 6 is attached from above to a through-hole 601 provided in the support substrate 60. In other words, the DMD 6 is attached to the upper surface (i.e., the main surface on the (+Z) side) of the support substrate 60 so as to overlap with the through-hole 601 in a plan view. In other words, the support substrate 60 is a device holder that holds the DMD 6.

[0045] The DMD 6 includes a DMD base section 61, a DMD mirror section 62, and a DMD cover section 63. The DMD base section 61 is a substantially flat plate-shaped member that extends substantially perpendicularly to the Z direction. That is, the Z direction is the thickness direction of the DMD base section 61 and also the thickness direction of the DMD 6. The shape of the DMD base section 61 in a plan view is, for example, substantially rectangular. The DMD base section 61 directly or indirectly contacts the upper surface of the support substrate 60 and is supported from below by the support substrate 60. The DMD base section 61 is provided with a receiving section that receives a drive signal input from outside the DMD 6, a drive section that drives the DMD mirror section 62 based on the drive signal, and the like.

[0046] The DMD mirror section 62 is provided on a main surface 611 on the (-Z) side of the DMD base section 61. The shape of the DMD mirror section 62 in a planar view is, for example, approximately rectangular. The size of the DMD mirror section 62 in a planar view is smaller than the size of the DMD base section 61 in a planar view. The entire DMD mirror section 62 is covered by the DMD base section 61 from the (+Z) side.

[0047] The DMD mirror section 62 includes a plurality of movable micromirrors (not shown) arranged in a matrix. The plurality of micromirrors are driven independently of one another by the driving section provided in the DMD base section 61, and can be switched between an ON state and an OFF state. The plurality of micromirrors are arranged in a substantially planar manner at substantially the same position in the Z direction. The plurality of micromirrors are arranged, for example, substantially parallel to the X direction and the Y direction. The DMD mirror section 62 is arranged inside the through-hole 601 of the support substrate 60. The lower surface of the DMD mirror section 62 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.

[0048] In the light modulation section 44, the light guided to the DMD 6 is incident on the DMD 6 from the (-Z) side of the DMD 6, reflected by the DMD mirror section 62, and guided to the (-Z) side of the DMD 6. That is, the (-Z) side of the DMD 6 (i.e., one side in the thickness direction) is the incident side (i.e., the front side) on which the light is incident, and the (+Z) side of the DMD 6 (i.e., the other side in the thickness direction) is the rear side located opposite to the incident side of the light. The main surface 612 on the (+Z) side of the DMD base section 61 is also the main surface on the (+Z) side of the DMD 6, and will be referred to as the "rear surface 612 of the DMD 6" in the following description. The main surface 612 on the (+Z) side of the DMD base section 61 is a substantially flat surface that is substantially perpendicular to the Z direction.

[0049] The DMD cover section 63 is a light-transmitting member, and covers the multiple micromirrors of the DMD mirror section 62 from below. The DMD cover section 63 is, for example, a substantially rectangular parallelepiped or substantially flat member with an opening on the (+Z) side. The DMD cover section 63 is attached to a main surface 611 on the (-Z) side of the DMD base section 61. The DMD cover section 63 is, for example, a cover glass made of transparent quartz glass. Light incident on the DMD 6 passes through the DMD cover section 63 and enters the DMD mirror section 62. Light reflected by the DMD mirror section 62 passes through the DMD cover section 63 and is guided to the outside of the DMD 6.

[0050] The DMD cover part 63 is disposed inside the through-hole 601 of the support substrate 60. A main surface 631 (i.e., the lower surface) on the (-Z) side of the DMD cover part 63 is located lower than the upper surface of the support substrate 60 around the through-hole 601 and higher than 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 part 63 is a substantially flat surface that is substantially perpendicular to the Z direction.

[0051] The cooling unit 7 is a mechanism for cooling the DMD 6. The cooling unit 7 includes a rear cooling unit 71, a biasing unit 72, and a front cooling unit 74. The rear cooling unit 71 is disposed on the (+Z) side of the DMD 6 (i.e., the side opposite the substrate 9 shown in FIG. 1) at a position overlapping with the DMD 6 in a plan view. The rear cooling unit 71 contacts a 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 thermal conduction. The biasing unit 72 is a member that biases the rear cooling unit 71 against the main surface 612 on the (+Z) side of the DMD base unit 61 (i.e., the rear surface 612 of the DMD 6). The front surface cooling section 74 is disposed on the (-Z) side of the DMD 6, and forms an airflow that flows along the (-Z) side principal surface 631 (i.e., the bottom surface) of the DMD cover section 63 to cool the DMD 6 from the DMD cover section 63 side. The (-Z) side principal surface 631 of the DMD cover section 63 is also the (-Z) side principal surface of the DMD 6, and will be referred to as the "front surface 631 of the DMD 6" in the following description.

[0052] The back surface cooling part 71 is a substantially rectangular parallelepiped member having a flow path 710 therein, and is a cooling jacket in which a fluid coolant flows through the flow path 710. The coolant is, for example, a liquid such as water. The coolant may be a liquid other than water, a gas, or a two-phase fluid in which a liquid and a gas are mixed. In this embodiment, the back surface cooling part 71 is a water-cooled jacket in which water flows through the flow path 710. In the example shown in FIG. 4, water flows into the flow path 710 from an opening provided at the end of the (+X) side on the upper surface (i.e., the (+Z) side surface) of the back surface cooling part 71, and the water in the flow path 710 is discharged from an opening provided at the end of the (-X) side on the upper surface of the back surface cooling part 71.

[0053] In the examples shown in FIG. 3 to FIG. 5, the shape of the back surface cooling part 71 in plan view is a substantially rectangular shape with a length in the X direction longer than the length in the Y direction. In other words, the shape of the back surface cooling part 71 in plan view is a substantially rectangular shape having a pair of long sides substantially parallel to the X direction and a pair of short sides substantially parallel to the Y direction. The length of the back surface cooling part 71 in the X direction is substantially constant except for the lower end part (i.e., the end part on the (-Z) side) of the back surface cooling part 71, and decreases at the lower end part of the back surface cooling part 71. The lower end part of the back surface cooling part 71 is provided with a convex part that protrudes downward from the substantially center part in the X direction (i.e., toward the back surface 612 of the DMD 6). The lower end surface of the convex part is indirectly in contact with the main surface 612 on the (+Z) side of the DMD base part 61 via a sheet-like heat transfer member 711. The heat transfer member 711 is a heat dissipation sheet having a relatively high thermal conductivity. The shape of the back surface cooling part 71 may be changed in various ways. Furthermore, the rear surface cooling section 71 may be in direct contact with the main surface 612 on the (+Z) side of the DMD base section 61 without using the heat transfer member 711 or the like.

[0054] The biasing part 72 is a substantially flat plate-shaped member disposed on the (+Z) side of the backside cooling part 71. The biasing part 72 contacts the upper surface of the backside cooling part 71 from the (+Z) side (i.e., the other side in the thickness direction of the DMD base part 61). In the example shown in Figs. 3 and 4, the biasing part 72 indirectly contacts the upper surface of the backside cooling part 71 via a substantially rectangular parallelepiped heat insulating member 721. The heat insulating member 721 is formed of, for example, resin, and suppresses heat conduction between the backside cooling part 71 and the biasing part 72. The biasing part 72 may be in direct contact with the backside cooling part 71 without the heat insulating member 721 or the like.

[0055] In the examples shown in Figs. 3 to 5, the shape of the urging part 72 in plan view is a substantially rectangular shape with a length in the Y direction longer than the length in the X direction. In other words, the shape of the urging part 72 in plan view is a substantially rectangular shape having a pair of long sides substantially parallel to the Y direction and a pair of short sides substantially parallel to the X direction. In plan view, the pair of long sides of the urging part 72 are substantially perpendicular to the pair of long sides of the back surface cooling part 71. The (+Y) side end of the urging part 72 protrudes from the back surface cooling part 71 to the (+Y) side in plan view, and the (-Y) side end of the urging part 72 protrudes from the back surface cooling part 71 to the (-Y) side in plan view. In other words, both ends of the urging part 72 in the Y direction extend from the back surface cooling part 71 in the Y direction in plan view.

[0056] The biasing unit 72 is indirectly connected to the support substrate 60 at both ends in the Y direction (i.e., both ends in a direction parallel to a pair of long sides of the biasing unit 72) via an intervening member 722 attached to the upper surface of the support substrate 60 by screwing or the like. Specifically, both ends in the Y direction of the biasing unit 72 are screwed to the intervening member 722 on the (+Y) side and (-Y) side of the back surface cooling unit 71 (i.e., fastened using two screws 723), thereby connecting the biasing unit 72 to the intervening member 722 and indirectly connecting to the support substrate 60 via the intervening member 722. As a result, a downward force acts on the back surface cooling unit 71 from the biasing unit 72 via the heat insulating member 721, and the back surface cooling unit 71 is biased against the main surface 612 on the (+Z) side of the DMD base unit 61. As a result, a temperature rise in the DMD base unit 61 is suitably suppressed. In other words, cooling of the DMD 6 from the DMD base portion 61 side by the rear surface cooling portion 71 is suitably achieved.

[0057] Each screw 723 is inserted into a helical spring 724 and is screwed into a screw hole of the interposed member 722, and the helical spring 724 is compressed between the screw head of the screw 723 and the interposed member 722. This equalizes the downward force acting on the back surface cooling unit 71 from the biasing unit 72 in the Y direction. As a result, the force biasing the back surface cooling unit 71 against the main surface 612 on the (+Z) side of the DMD base unit 61 is equalized in the contact area between the back surface cooling unit 71 and the main surface 612, and the back surface cooling unit 71 contacts the DMD base unit 61 favorably. This allows the back surface cooling unit 71 to more favorably cool the DMD 6 from the DMD base unit 61 side.

[0058] The force with which the back surface cooling section 71 is urged against the main surface 612 on the (+Z) side of the DMD base section 61 (hereinafter also referred to as the "back surface urging force") has an upper limit set in relation to the structure of the DMD 6, etc. The above-mentioned helical spring 724 is selected so that the back surface urging force does not exceed the upper limit. The thermal conductivity, thickness, etc. of the above-mentioned heat transfer member 711 are also set so that a sufficient heat transfer effect (i.e., heat dissipation effect) is obtained with the back surface urging force.

[0059] In the example shown in FIG. 3 and FIG. 4, the intervening member 722 is a member that protrudes from the upper surface of the support substrate 60 to the (+Z) side (i.e., the side where the back surface cooling unit 71 is arranged). The intervening member 722 includes a first member 725 and a second member 726. The second member 726 of the intervening member 722 is a substantially flat plate-like member that is substantially perpendicular to the Z direction and is fixed to the upper surface of the support substrate 60. The shape of the second member 726 in a plan view is a substantially rectangular frame shape with a through hole provided in the center. The lower end of the back surface cooling unit 71 is inserted into the through hole of the second member 726. This suppresses deviation of the relative position of the back surface cooling unit 71 with respect to the support substrate 60. The lower end of the back surface cooling unit 71 contacts the main surface 612 on the (+Z) side of the DMD base unit 61 through the through hole of the second member 726.

[0060] A first member 725 of the interposed member 722 is fixed to an upper surface of the second member 726 (i.e., the main surface on the (+Z) side opposite the support substrate 60). The first member 725 is an annular member in which a substantially flat plate-like portion is bent and continues in an annular shape. The first member 725 is a continuous member that includes a pair of support portions 727 and a pair of connecting portions 728.

[0061] The pair of support parts 727 are disposed on the (+Y) side and the (-Y) side of the back surface cooling part 71. Each support part 727 is a gate-shaped part that opens toward the (-Z) side (i.e., toward the second member 726 and the support substrate 60). The shape of each support part 727 can also be regarded as a substantially U-shaped part that opens toward the (-Z) side. Each support part 727 protrudes from the upper surface of the second member 726 toward the (+Z) side (i.e., the side opposite the support substrate 60). Each support part 727 can also be regarded as a protrusion that protrudes from the support substrate 60 toward the (+Z) side. The shape of each support part 727 in a plan view is a substantially rectangular belt shape that extends substantially parallel to the X direction. The size of each support part 727 in the X direction is smaller than the size of the back surface cooling part 71 in the X direction.

[0062] The pair of connecting portions 728 are generally flat plate-shaped portions generally perpendicular to the Z direction, and connect the lower ends of the pair of supporting portions 727 to each other at both ends in the X direction of the pair of supporting portions 727. The shape of each connecting portion 728 in a plan view is a generally rectangular strip extending generally parallel to the Y direction. Each connecting portion 728 is fixed in direct contact with the upper surface of the second member 726. For example, each connecting portion 728 is fixed to the supporting substrate 60 by screws or the like, with the second member 726 sandwiched between each connecting portion 728 and the supporting substrate 60.

[0063] An upper end 727a (i.e., the end on the (+Z) side) of each support portion 727 is a generally flat plate-shaped portion that is generally perpendicular to the Z direction. A Y-direction end of the biasing portion 72 is connected to the center in the X direction of the upper end 727a of each support portion 727 by the above-mentioned screw 723. The portion of the upper end 727a of each support portion 727 to which the biasing portion 72 is connected is located above the upper end of the back surface cooling portion 71 in the vertical direction (i.e., on the opposite side to the DMD 6 across the back surface cooling portion 71 in the vertical direction).

[0064] In each support portion 727, a pair of legs 727b extending downward from both ends in the X direction of the upper end portion 727a are approximately flat plate-shaped portions approximately perpendicular to the X direction. The lower end of each leg 727b is continuous with the above-mentioned connecting portion 728. In the (-Y) side support portion 727 of the pair of support portions 727, the pair of legs 727b faces the (-Y) side side surface of the back surface cooling portion 71 in the Y direction and is disposed close to or in contact with the side surface. In the (+Y) side support portion 727 of the pair of support portions 727, the pair of legs 727b faces the (+Y) side side surface of the back surface cooling portion 71 in the Y direction and is disposed close to or in contact with the side surface. That is, the pair of legs 727b of each support portion 727 extends in the vertical direction along the Y direction side surface of the back surface cooling portion 71.

[0065] The back surface cooling unit 71 is supported by being sandwiched between a pair of support parts 727 in the Y direction. Specifically, the back surface cooling unit 71 is supported from the Y direction by a pair of legs 727b of each support part 727. As described above, the back surface cooling unit 71 is a substantially rectangular parallelepiped that is long in the X direction and short in the Y direction, and therefore is relatively prone to falling in the Y direction if not supported by other members. In the drawing device 1, the back surface cooling unit 71 is supported from the (+Y) side and the (-Y) side by the pair of support parts 727, so that the back surface cooling unit 71 is suppressed from tilting in the Y direction and is prevented from falling in the Y direction. In addition, when the biasing part 72 is screwed to the interposed member 722, the back surface cooling unit 71 is also suppressed from tilting due to the order in which the screws 723 are fastened, etc.

[0066] The shapes and structures of the intervening member 722 and the biasing portion 72 may be modified in various ways. For example, the first member 725 and the second member 726 of the intervening member 722 may be a continuous member. Alternatively, the first member 725 of the intervening member 722 does not necessarily have to be a continuous member, and may be divided into a plurality of members. Furthermore, the biasing portion 72 may be directly connected to the support substrate 60 without the intervening member 722 or the like.

[0067] The housing member 8 is a lidded cylindrical (i.e., box-shaped) member that opens downward. In the example shown in FIG. 4, the housing member 8 has an outer shape of a substantially rectangular parallelepiped, and includes a top portion 81 and a side wall portion 82. The top portion 81 of the housing member 8 is a substantially flat portion that extends substantially perpendicularly in the Z direction. The side wall portion 82 of the housing member 8 is a substantially flat portion that extends downward from the outer periphery of the top portion 81 over the entire circumference. The housing member 8 is attached to the upper surface of the support substrate 60, covering the back surface cooling portion 71, the biasing portion 72, the intervening member 722, and the like. As a result, the back surface cooling portion 71, the biasing portion 72, the intervening member 722, and the like are accommodated in the internal space 80 of the housing member 8. The outer shape of the housing member 8 is not necessarily limited to a substantially rectangular parallelepiped shape, and may be another shape (for example, a substantially cylindrical shape, a substantially polygonal prism shape, a dome shape, or the like).

[0068] An air inlet 83 to which a duct extending from a dry gas supply source (not shown) is connected is provided in the side wall 82 of the storage member 8. A dry gas having a dew point lower than that of the atmosphere around the storage member 8 (i.e., the space outside the storage member 8) is supplied to the internal space 80 of the storage member 8 through the air inlet 83. This suppresses condensation on the surface of the back surface cooling unit 71 and the like, and suppresses moisture from adhering to the DMD 6. The dry gas supplied to the internal space 80 of the storage member 8 is exhausted to the outside of the storage member 8 through an exhaust port 84 provided in the side wall 82 of the storage member 8 at a distance from the air inlet 83. The above-mentioned dry gas is, for example, CDA (clean dry air). The dry gas may be, for example, an inert gas such as nitrogen (N2).

[0069] The front surface cooling unit 74 includes a first nozzle 741 and a second nozzle 742. The first nozzle 741 and the second nozzle 742 are connected to a gas supply source (not shown) and supply gas to the DMD cover unit 63 to suppress a rise in temperature of the DMD cover unit 63 and the DMD mirror unit 62. The gas is, for example, compressed air or the above-mentioned dry gas. When dry gas is supplied to the DMD cover unit 63, the first nozzle 741 and the second nozzle 742 and the above-mentioned air supply port 83 may be connected to the same dry gas supply source.

[0070] The first nozzle 741 and the second nozzle 742 are provided inside the support substrate 60, and their respective tips protrude from the inner circumferential surface 602 of the through hole 601 of the support substrate 60 toward the space inside the through hole 601 (i.e., the space surrounded by the inner circumferential surface 602 of the through hole 601). An ejection port 743 (hereinafter also referred to as the "first ejection port 743") of the first nozzle 741 is provided on the inner circumferential surface 602 of the through hole 601, closer to the (-Y) side than the DMD cover portion 63 and the DMD mirror portion 62. An ejection port 744 (hereinafter also referred to as the "second ejection port 744") of the second nozzle 742 is provided on the inner circumferential surface 602 of the through hole 601, closer to the (+Y) side than the DMD cover portion 63 and the DMD mirror portion 62. 5, the first ejection port 743 is disposed near the end on the (-Y) side of the through hole 601, and the second ejection port 744 is disposed near the end on the (+Y) side of the through hole 601. In other words, the first ejection port 743 and the second ejection port 744 are approximately opposed to each other in the Y direction, sandwiching the DMD cover portion 63 and the DMD mirror portion 62 therebetween. The first ejection port 743 and the second ejection port 744 eject gas approximately parallel to the Y direction.

[0071] The flow of gas ejected from the first nozzle 743 (hereinafter also referred to as the "first airflow") flows along the (-Z) side main surface 631 of the DMD cover section 63 (i.e., the front surface 631 of the DMD 6) from the (-Y) side to the (+Y) side, approximately parallel to the Y direction. The flow of gas ejected from the second nozzle 744 (hereinafter also referred to as the "second airflow") flows along the (-Z) side main surface 631 of the DMD cover section 63, approximately parallel to the Y direction from the (+Y) side to the (-Y) side. In this embodiment, the first airflow and the second airflow flow approximately parallel to the (-Z) side main surface 631 of the DMD cover section 63. The temperatures of the first airflow and the second airflow are lower than the temperatures of the DMD cover section 63 and the DMD mirror section 62 of the DMD 6 during operation, so that the DMD cover section 63 and the DMD mirror section 62 are suitably cooled. Furthermore, the first airflow and the second airflow are formed in the space inside through-hole 601, and the gas is less likely to diffuse into the surrounding space, so that DMD cover portion 63 and DMD mirror portion 62 are cooled even more effectively.

[0072] 2, the incident direction of light incident on the DMD 6 from the illumination optical system 43 via the mirrors 471 and 472 is an upper right direction in FIG. 2 (i.e., an oblique direction proceeding toward the (+Y) side and the (+Z) side). In other words, the incident direction is inclined toward the (-Y) direction with respect to the Z direction (i.e., the thickness direction of the DMD base portion 61). In further other words, the incident direction is approximately parallel to the YZ plane, and is inclined with respect to both the Y direction and the Z direction within the YZ plane.

[0073] For this reason, while drawing apparatus 1 is drawing on substrate 9, the amount of light irradiated onto DMD mirror section 62 may become uneven in the Y direction (hereinafter also referred to as the "lateral direction"), which may cause uneven temperature distribution in the Y direction of DMD mirror section 62. As described above, in front-side cooling section 74 shown in Fig. 5, the flow direction of the airflow (i.e., the first airflow and the second airflow) formed by front-side cooling section 74 is approximately parallel to the Y direction, so that the temperature difference in the Y direction of DMD 6 caused by the uneven temperature distribution is suppressed.

[0074] 6 is a bottom view of the portion of the optical modulation section 44 near the DMD 6 as viewed from the (-Z) side. As shown in FIG. 6, the positions of the first outlet 743 of the first nozzle 741 and the second outlet 744 of the second nozzle 742 arranged around the through hole 601 of the support substrate 60 in the X direction (i.e., the direction perpendicular to the lateral direction and thickness direction) are different. Specifically, with respect to an imaginary straight line L1 that passes through the center of the through hole 601 in a plan view and extends in the Y direction, the first outlet 743 is slightly shifted to the (+X) side, and the second outlet 744 is slightly shifted to the (-X) side. This prevents the first airflow and the second airflow from colliding with each other near the DMD cover section 63 (i.e., near the main surface 631 on the (-Z) side of the DMD cover section 63), and cooling of the DMD cover section 63 and the DMD mirror section 62 is suitably achieved.

[0075] As described above, the optical device 10 that irradiates the object with modulated light includes the illumination optical system 43, the light modulation unit 44, and the projection optical system 45. The illumination optical system 43 receives light emitted from the light source 421. The light modulation unit 44 modulates the light guided by the illumination optical system 43. The projection optical system 45 guides the light modulated by the light modulation unit 44 to the object (substrate 9 in the above example). The light modulation unit 44 includes the DMD 6, a support substrate 60, and a cooling unit 7. The support substrate 60 is provided with a through hole 601 to which the DMD 6 is attached. The cooling unit 7 cools the DMD 6. The DMD 6 includes a DMD base portion 61, a DMD mirror portion 62, and a DMD cover portion 63. The DMD mirror portion 62 includes a plurality of movable micromirrors arranged in a matrix on one side of the thickness direction of the DMD base portion 61 (the (-Z) side in the above example). The DMD cover section 63 covers the DMD mirror section 62 from one side in the thickness direction.

[0076] The cooling section 7 includes a back surface cooling section 71 and a biasing section 72. The back surface cooling section 71 contacts a main surface 612 on the other side in the thickness direction of the DMD base section 61 (the (+Z) side in the above example) and cools the DMD 6 by thermal conduction. The biasing section 72 contacts the back surface cooling section 71 from the other side in the thickness direction. The biasing section 72 is connected to the support substrate 60, thereby biasing the back surface cooling section 71 against the main surface 612 on the other side in the thickness direction of the DMD base section 61 (i.e., the back surface 612 of the DMD 6).

[0077] This eliminates the need to provide the backside cooling section 71 with a structure such as a flange for biasing the backside cooling section 71 against the DMD base section 61, and allows the DMD 6 to be cooled from the DMD base section 61 side while simplifying the structure of the backside cooling section 71. As a result, the temperature on the backside 612 side of the DMD 6 can be maintained within a range of a predetermined operating temperature condition, and shortening of the life of the DMD 6 can be suppressed. This reduces the frequency of replacement of the DMD 6 in the optical device 10.

[0078] As described above, the urging part 72 is indirectly connected to the support substrate 60 by being connected to the intervening member 722 protruding from the support substrate 60 to the other side in the thickness direction. It is preferable that the portion where the urging part 72 and the intervening member 722 are connected is located on the other side of the end of the back surface cooling part 71 in the thickness direction (the (+Z) side in the above example). This allows an operator or the like replacing the DMD 6 to easily access the connection part between the urging part 72 and the intervening member 722. This makes it easy to attach and detach the urging part 72 to and from the support substrate 60, and simplifies the replacement work of the DMD 6.

[0079] As described above, the biasing portion 72 is indirectly connected to the support substrate 60 by being connected to the intervening member 722 protruding from the support substrate 60 to the other side in the thickness direction. The intervening member 722 preferably includes a pair of support portions 727 that extend in the thickness direction (Z direction in the above example) along the side surfaces of the back surface cooling portion 71 and support the back surface cooling portion 71 by sandwiching it therebetween. In addition, the biasing portion 72 is preferably connected to the end portions on the other side (the (+Z) side in the above example) of the pair of support portions 727 in the thickness direction. This makes it possible to suppress tilting of the back surface cooling portion 71 as described above.

[0080] As described above, the biasing portion 72 is indirectly connected to the support substrate 60 by being connected to the intervening member 722 protruding from the support substrate 60 to the other side in the thickness direction. The intervening member 722 preferably includes a gate-shaped protruding portion (the support portion 727 in the above example) that protrudes from the support substrate 60 to the other side in the thickness direction and opens toward the support substrate 60. The biasing portion 72 is preferably connected to an end portion on the other side (the (+Z) side in the above example) of the protruding portion in the thickness direction. Thereby, when the back surface cooling portion 71 is biased by the biasing portion 72, the protruding portion elastically deforms in the Z direction, and the biasing portion 72 can suitably apply a force to the back surface cooling portion 71. As a result, the back surface cooling portion 71 can be suitably biased against the DMD base portion 61.

[0081] As described above, the back surface cooling unit 71 and the biasing unit 72 each have a rectangular shape in a plan view parallel to the thickness direction (Z direction in the above example). Preferably, a pair of long sides of the biasing unit 72 are perpendicular to a pair of long sides of the back surface cooling unit 71 in a plan view. In addition, the biasing unit 72 is preferably connected to the support substrate 60 at both ends in a direction parallel to the pair of long sides of the biasing unit 72 (Y direction in the above example). This allows the biasing unit 72 to suitably apply force to the back surface cooling unit 71. As a result, the back surface cooling unit 71 can be suitably biased against the DMD base unit 61.

[0082] As described above, the optical modulation section 44 preferably further includes a tubular storage member 8 with a lid. The storage member 8 is disposed on the other side of the support substrate 60 in the thickness direction (the (+Z) side in the above example). The storage member 8 covers the back surface cooling section 71 and stores it in the internal space 80. It is preferable that a dry gas is supplied to the internal space 80 of the storage member 8. This makes it possible to suppress condensation in the back surface cooling section 71.

[0083] As described above, it is preferable that the cooling section 7 further includes a front cooling section 74 that forms an airflow along the main surface 631 on one side in the thickness direction of the DMD cover section 63 (the (-Z) side in the above example) to cool the DMD 6. This allows the DMD 6 to be cooled from the DMD cover section 63 side (i.e., the front surface 631 side of the DMD 6). As a result, the temperature on the front surface 631 side of the DMD 6 can be maintained within a range of a predetermined operating temperature condition, and the temperature difference between the front surface 631 side and the rear surface 612 side of the DMD 6 can also be maintained within a range of a predetermined operating temperature condition. This further suppresses the life of the DMD 6 from being shortened, and further reduces the frequency of replacing the DMD 6 in the optical device 10.

[0084] As described above, the flow direction of the airflow formed by the front-surface cooling section 74 is preferably parallel to the main surface 631 on one side in the thickness direction of the DMD cover section 63 (the (-Z) side in the above example). This makes it possible to suitably suppress stagnation of the atmosphere in the vicinity of the main surface 631 of the DMD cover section 63, and as a result, it is possible to suitably cool the DMD 6.

[0085] As described above, the direction of incidence of light on the DMD 6 is inclined in the lateral direction (Y direction in the above example) perpendicular to the thickness direction (Z direction in the above example) with respect to the thickness direction. The flow direction of the airflow formed by the front cooling unit 74 is preferably parallel to the lateral direction. This makes it possible to suppress the lateral temperature difference in the DMD 6 as described above.

[0086] As described above, it is preferable that the airflow formed by the front surface cooling section 74 includes a first airflow flowing from one side to the other side in the horizontal direction perpendicular to the thickness direction (in the above example, from the (-Y) side to the (+Y) side), and a second airflow flowing from the other side to one side in the horizontal direction (in the above example, from the (+Y) side to the (-Y) side). This allows gas from the front surface cooling section 74 to be evenly supplied to substantially the entire main surface 631 on the (-Z) side of the DMD cover section 63. As a result, the temperature difference in the horizontal direction in the DMD 6 can be further suppressed.

[0087] As described above, in the direction perpendicular to the thickness direction and the lateral direction (the X direction in the above example), it is preferable that the position of the first outlet 743 that forms the first airflow and the position of the second outlet 744 that forms the second airflow are different from each other. This makes it possible to suppress collision between the first airflow and the second airflow near the DMD cover part 63, and therefore makes it possible to preferably cool the DMD 6 from the front surface 631 side.

[0088] The above-mentioned drawing apparatus 1 draws a pattern by irradiating light onto the substrate 9. The drawing apparatus 1 includes a stage 21, the above-mentioned optical device 10, and a scanning mechanism (stage moving mechanism 22 in the above example). The stage 21 holds the substrate 9. The optical device 10 irradiates the substrate 9 with modulated light. The scanning mechanism moves the stage 21 relative to the optical device 10 in a scanning direction (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, the DMD 6 can be cooled while simplifying the structure of the back surface cooling unit 71, and therefore the frequency of replacement of the DMD 6 can be reduced. Therefore, the structure of the drawing apparatus 1 can be simplified, and the frequency of maintenance of the drawing apparatus 1 related to the optical device 10 can also be reduced.

[0089] The optical device 10 and the imaging device 1 described above can be modified in various ways.

[0090] For example, in the front cooling section 74, the flow direction of the first airflow and / or the second airflow does not necessarily have to be parallel to the main surface 631 on the (-Z) side of the DMD cover section 63; for example, gas may be ejected diagonally upwards toward the main surface 631 from the first outlet 743 and / or the second outlet 744 arranged diagonally below the main surface 631 on the (-Z) side of the DMD cover section 63.

[0091] In the front cooling section 74, the positions of the first and second ejection ports 743 and 744 are not limited to the above example and may be changed in various ways. For example, the first and second ejection ports 743 and 744 may be disposed on the above-mentioned imaginary straight line L1 (see FIG. 6). Also, for example, the first ejection port 743 may be disposed near the end of the through hole 601 on the (+X) side, and the second ejection port 744 may be disposed near the end of the through hole 601 on the (-X) side.

[0092] Furthermore, one of the first ejection port 743 and the second ejection port 744 may be omitted in the front surface cooling portion 74. Alternatively, in addition to the first ejection port 743 and the second ejection port 744, another ejection port may be provided.

[0093] In the above-described cooling unit 7, the shapes and structures of the biasing portion 72 and the intervening member 722, as well as the connection position and connection structure of the biasing portion 72 to the intervening member 722, are not limited to the above examples and may be modified in various ways. For example, the support portion 727 of the intervening member 722 does not necessarily have to be gate-shaped, and may be, for example, a substantially flat plate shape extending substantially perpendicularly to the Y direction. In addition, the connection portion between the intervening member 722 and the biasing portion 72 may be located at the same position as the upper end of the back surface cooling unit 71, or below the upper end (i.e., on the (-Z) side).

[0094] In the interposed member 722, a pair of support parts 727 that support the back surface cooling part 71 from the sides may not necessarily be provided, and for example, a pair of protrusion parts spaced apart from the back surface cooling part 71 in the Y direction may be provided, and both ends in the Y direction of the urging part 72 may be connected to the pair of protrusion parts. Alternatively, a pair of support parts 727 that support the back surface cooling part 71 from the sides may be provided separately from the pair of protrusion parts to which the urging part 72 is connected.

[0095] The shape of the biasing part 72 may be, for example, a substantially rectangular parallelepiped shape. In addition, in the cooling part 7, the interposed member 722 may not be provided, and the two lower ends of the substantially gate-shaped (i.e., substantially U-shaped) biasing part 72 spanning the back surface cooling part 71 may be directly connected to the support substrate 60.

[0096] In the above-described cooling unit 7, a substantially rectangular parallelepiped water-cooling jacket is used as the back surface cooling unit 71, but the shape, structure, type, and the like of the back surface cooling unit 71 may be modified in various ways. For example, the shape of the back surface cooling unit 71 may be substantially cylindrical or substantially polygonal prism, or may be substantially flat. The positions of the coolant inlet and outlet with respect to the flow path 710 of the back surface cooling unit 71 may also be modified in various ways. Alternatively, cooling of the DMD 6 from the DMD base unit 61 side does not necessarily have to be performed by the coolant flowing through the flow path 710 of the back surface cooling unit 71, and may be performed by other configurations such as a Peltier element, for example.

[0097] FIG. 7 is a side view showing the configuration of the light modulation section 44a in which a Peltier element is provided as the back surface cooling section 71a. In the light modulation section 44a, the lower surface, which is the heat absorbing surface of the back surface cooling section 71a, which is a Peltier element, indirectly contacts the (+Z) side main surface 612 (i.e., the back surface 612 of the DMD 6) of the DMD base section 61 of the DMD 6 supported by the support substrate 60 via the heat transfer member 711a. In addition, the substantially flat plate-shaped biasing section 72a contacts the upper surface (i.e., the (+Z) side main surface) of the back surface cooling section 71a from above. The biasing section 72a biases the back surface cooling section 71a against the (+Z) side main surface 612 of the DMD base section 61 by being connected to the support substrate 60 with a screw 723. This allows the DMD 6 to be cooled from the DMD base section 61 side while simplifying the structure of the back surface cooling section 71a.

[0098] In the optical modulation section 44a, a water-cooled jacket 75 is provided above the biasing section 72a. The water-cooled jacket 75 contacts the upper surface of the biasing section 72a from above and cools the upper surface, which is the heat generating surface of the back surface cooling section 71a, via the biasing section 72a. This makes it possible to suitably achieve cooling of the DMD 6 by the back surface cooling section 71a.

[0099] In the optical modulation unit 44a, similarly to the optical modulation unit 44 described above, the housing member 8 is attached to the upper surface of the support substrate 60. The back surface cooling unit 71a, the biasing unit 72a, the water-cooled jacket 75, and the like are housed in the internal space 80 of the housing member 8. The above-mentioned dry gas is supplied to the internal space 80 of the housing member 8. This suppresses condensation on the surfaces of the back surface cooling unit 71a, the water-cooled jacket 75, and the like.

[0100] In the light modulation section 44a, the supply of dry gas to the internal space 80 of the housing member 8 is not necessarily performed. In this case, the housing member 8 may be omitted from the light modulation section 44a. The same applies to the light modulation section 44.

[0101] In the optical device 10, the front cooling portion 74 may be omitted.

[0102] In the imaging device 1, the stage 21 may be moved relatively in the main scanning direction with respect to the imaging head 41 by the first moving mechanism 23. Therefore, for example, the stage 21 may be fixed, and above the stage 21, the imaging head 41 may be moved in the main scanning direction by the first moving mechanism 23. Similarly, the imaging head 41 may be moved in the sub-scanning direction by the second moving mechanism 24.

[0103] The above-mentioned substrate 9 is not necessarily limited to a printed circuit board. The drawing device 1 may draw a pattern on, for example, a semiconductor substrate, a substrate for a semiconductor package, a glass substrate for a flat panel display device such as a liquid crystal display device or a plasma display device, a glass substrate for a photomask, a substrate for a solar panel, or the like.

[0104] The optical device 10 may be used as a device that irradiates modulated light onto a substrate 9 in a drawing device having a structure different from that of the above-described drawing device 1. Alternatively, the optical device 10 may be used to irradiate an object with modulated light in a device other than a drawing device.

[0105] The configurations in the above-described embodiment and each of the modified examples may be combined as appropriate as long as they are not mutually inconsistent. [Explanation of symbols]

[0106] 1 Drawing device 6 DMD (Digital Micromirror Device) 7 Cooling section 8. Storage material 9 Substrate 10 Optical equipment 21 Stage 22 Stage movement mechanism 43 Illumination optical system 44, 44a Optical modulation section 45 Projection optical system 60 Support substrate 61 DMD base section 62 DMD mirror section 63 DMD cover part 71,71a Rear cooling section 72,72a Force section 74 Front cooling section 80 Interior Space 421 Light source 601 Through hole 612 (DMD base) Main surface 631 (DMD cover) main surface 722 Intervening member 727 Support part 727a (upper end of support) 743 No. 1 spout 744 2nd spout

Claims

1. An optical device for illuminating an object with modulated light, comprising: 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; a projection optical system that guides the light modulated by the light modulation unit to an object; Equipped with The optical modulation unit is A digital micromirror device; a support substrate having a through hole to which the digital micromirror device is attached; a cooling unit that cools the digital micromirror device; Equipped with The digital micromirror device is A DMD base portion; a DMD mirror section including a plurality of movable micromirrors arranged in a matrix on one side in a thickness direction of the DMD base section; a DMD cover portion that covers the DMD mirror portion from the one side in the thickness direction; Equipped with The cooling unit includes: a back surface cooling section that is in contact with the other main surface of the DMD base section in the thickness direction and that cools the digital micromirror device by thermal conduction; a biasing portion that contacts the rear surface cooling portion from the other side in the thickness direction and is connected to the support substrate to bias the rear surface cooling portion against the main surface of the other side in the thickness direction of the DMD base portion; An optical device comprising:

2. 2. The optical device according to claim 1, the biasing portion is indirectly connected to the support substrate by being connected to an intervening member protruding from the support substrate to the other side in the thickness direction, The optical device has a portion where the biasing portion and the interposition member are connected, the portion being located on the other side of the other end of the back surface cooling portion in the thickness direction.

3. 2. The optical device according to claim 1, the biasing portion is indirectly connected to the support substrate by being connected to an intervening member protruding from the support substrate to the other side in the thickness direction, the interposition member includes a pair of support parts extending in the thickness direction along side surfaces of the back surface cooling part and supporting the back surface cooling part by sandwiching the back surface cooling part therebetween, The biasing portion is connected to the other end of the pair of support portions in the thickness direction.

4. 2. The optical device according to claim 1, the biasing portion is indirectly connected to the support substrate by being connected to an intervening member protruding from the support substrate to the other side in the thickness direction, the interposition member includes a gate-shaped protrusion that protrudes from the support substrate to the other side in the thickness direction and opens toward the support substrate, The biasing portion is connected to the other end of the protrusion in the thickness direction.

5. 2. The optical device according to claim 1, The rear surface cooling portion and the biasing portion each have a rectangular shape in a plan view parallel to the thickness direction, In a plan view, a pair of long sides of the biasing portion are perpendicular to a pair of long sides of the back surface cooling portion, The biasing portion is connected to the support substrate at both ends in a direction parallel to the pair of long sides of the biasing portion.

6. 2. The optical device according to claim 1, The optical device further includes a covered cylindrical housing member, the optical modulation unit being arranged on the other side of the support substrate in the thickness direction, covering the back surface cooling unit and housing it in an internal space, and through which dry gas is supplied to the internal space.

7. 2. The optical device according to claim 1, The optical device further includes a front cooling section, wherein the cooling section forms an airflow along the main surface on the one side in the thickness direction of the DMD cover section to cool the digital micromirror device.

8. 8. The optical device according to claim 7, An optical device, wherein the flow direction of the airflow formed by the front surface cooling section is parallel to the main surface on the one side in the thickness direction of the DMD cover section.

9. 8. The optical device according to claim 7, an incident direction of light on the digital micromirror device is inclined with respect to the thickness direction in a lateral direction perpendicular to the thickness direction; An optical device, wherein the flow direction of the airflow formed by the front surface cooling portion is parallel to the lateral direction.

10. 8. The optical device according to claim 7, The airflow formed by the front surface cooling portion is A first air flow that flows from one side to the other side in a lateral direction perpendicular to the thickness direction; A second airflow flowing from the other side to the one side in the lateral direction; An optical device comprising:

11. 11. The optical device according to claim 10, An optical device, wherein a position of a first outlet that forms the first air flow and a position of a second outlet that forms the second air flow are different from each other in a direction perpendicular to the thickness direction and the lateral direction.

12. A drawing apparatus that draws a pattern by irradiating a substrate with light, A stage for holding the substrate; an optical device according to claim 1 , which irradiates the substrate with modulated light; a scanning mechanism that moves the stage relative to the optical device in a scanning direction parallel to a main surface of the substrate; A drawing device comprising:

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