Light source unit, illumination unit, exposure device, and exposure method

Abstract

This light source unit is provided with a heat sink and a plurality of light source elements arranged two-dimensionally on a first surface of the heat sink, wherein a plurality of protrusions that protrude from the first surface and that each overlap with at least one of the plurality of light source elements in plan view are formed on the first surface of the heat sink.

Description

Light source unit, illumination unit, exposure apparatus, and exposure method

[0001] The present invention relates to a light source unit, an illumination unit, an exposure apparatus, and an exposure method.

[0002] In recent years, liquid crystal display panels have come into widespread use as display elements for personal computers, televisions, and other devices. Liquid crystal display panels are manufactured by forming a thin-film transistor circuit pattern on a plate (glass substrate) using photolithography. An exposure apparatus is used for this photolithography process, which projects and exposes an original pattern formed on a mask onto a photoresist layer on the plate via a projection optical system.

[0003] It has been proposed to use a light source using a light emitting diode in various optical devices including the above-mentioned exposure device (for example, Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2006-201476

[0005] According to a first aspect of the disclosure, the light source unit comprises a heat sink and a plurality of light source elements arranged two-dimensionally on a first surface of the heat sink, and the first surface of the heat sink is formed with a plurality of protrusions that protrude from the first surface and each overlap with at least one of the plurality of light source elements in a planar view.

[0006] According to a second aspect of the disclosure, an illumination unit includes the light source unit and an illumination optical system that guides light emitted from the light source unit to an object to be illuminated.

[0007] According to a third aspect of the disclosure, the lighting unit comprises a plurality of the above-mentioned light source units, and an illumination optical system including a combining optical element that combines light emitted from the plurality of light source units and directs the combined light emitted from the combining optical element to an illuminated object.

[0008] According to a fourth aspect of the disclosure, an exposure apparatus includes the above-mentioned illumination unit and a projection optical system that projects a pattern image of a mask illuminated by the illumination unit onto a photosensitive substrate.

[0009] According to a fifth aspect of the disclosure, an exposure method is an exposure method using the above-mentioned exposure apparatus, and includes illuminating a mask with the illumination unit and projecting a pattern image of the mask onto a photosensitive substrate using the projection optical system.

[0010] The configurations of the embodiments described below may be modified as appropriate, and at least a portion of the configuration may be replaced with other components. Furthermore, components that are not particularly limited in terms of their placement may be placed in any position that can achieve their function, not limited to the placement disclosed in the embodiments.

[0011] FIG. 1 is a schematic diagram showing the configuration of an exposure apparatus according to a first embodiment. FIG. 2 is a schematic diagram showing the configuration of an illumination unit. FIG. 3(A) is a plan view schematically showing the configuration of a heat sink, and FIG. 3(B) is a cross-sectional view taken along line A-A in FIG. 3(A). FIG. 4(A) is a plan view schematically showing the state in which a first light source array and a second light source array are mounted on a heat sink, and FIG. 4(B) is a cross-sectional view taken along line A-A in FIG. 4(A). FIG. 4(C) is an enlarged view of the portion surrounded by circle C1 in FIG. 4(B). FIG. 5(A) is a further enlarged view of the portion surrounded by circle C1 in FIG. 4(B), and FIG. 5(B) is an equivalent circuit diagram of the first light source unit and the second light source unit according to the first embodiment. FIG. 6 is a diagram for explaining the first and second magnifying optical systems. FIG. 7A is a plan view showing a heat sink according to Modification 1 of the first embodiment, and FIG. 7B is a plan view showing a state in which a first light source array and a second light source array are mounted on the heat sink according to Modification 1. FIG. 8A is a plan view showing a heat sink according to Modification 2 of the first embodiment, and FIG. 8B is a plan view showing a state in which a first light source array and a second light source array are mounted on the heat sink according to Modification 2. FIG. 9A is a plan view illustrating a heat sink according to a second embodiment, and FIG. 9B is a cross-sectional view taken along line A-A in FIG. 9A. FIG. 10A is a plan view illustrating a heat sink according to Modification 1 of the second embodiment, and FIG. 10B is a cross-sectional view taken along line A-A in FIG. 10A. FIG. 11A is a plan view illustrating a heat sink according to Modification 2 of the second embodiment, and FIG. 11B is a cross-sectional view taken along line A-A in FIG. 11A. FIG. 12 is a cross-sectional view illustrating a heat sink according to a third embodiment. Fig. 13 is a diagram showing a preferable configuration of an illumination unit when using a heat sink according to the third embodiment. Fig. 14(A) is a plan view schematically showing the configuration of a heat sink according to a fourth embodiment, and Fig. 14(B) is a cross-sectional view taken along line A-A in Fig. 14(A). Fig. 15(A) is a plan view schematically showing a state in which a first light source array and a second light source array are mounted on a heat sink according to the fourth embodiment, Fig. 15(B) is a cross-sectional view taken along line A-A in Fig. 15(A), and Fig. 15(C) is an enlarged view of the portion surrounded by ellipse C1 in Fig. 15(B).Fig. 16 is an equivalent circuit diagram of the first light source unit and the second light source unit according to the fourth embodiment. Fig. 17(A) is a plan view schematically showing the configuration of a heat sink according to a modification of the fourth embodiment, and Fig. 17(B) is a cross-sectional view taken along line A-A in Fig. 17(A). Fig. 18(A) is a plan view schematically showing the state in which the first light source array and the second light source array are mounted on the heat sink according to the modification of the fourth embodiment, Fig. 18(B) is a cross-sectional view taken along line A-A in Fig. 18(A), and Fig. 18(C) is an enlarged view of the portion surrounded by ellipse C1 in Fig. 18(B). Fig. 19 is an equivalent circuit diagram of the first light source unit and the second light source unit according to the modification of the fourth embodiment.

[0012] First Embodiment An exposure apparatus 10 according to a first embodiment will be described with reference to FIGS. 1 to 6. FIG.

[0013] (Configuration of Exposure Apparatus) FIG. 1 is a diagram that shows roughly the configuration of an exposure apparatus 10 according to the first embodiment.

[0014] The exposure apparatus 10 is a scanning stepper (scanner) that drives a mask MSK and a glass substrate (hereinafter referred to as "plate") P in the same direction and at the same speed relative to a projection optical system PL, thereby transferring a pattern formed on the mask MSK onto the plate P. The plate P is a rectangular glass substrate used in, for example, a liquid crystal display device (flat panel display), and has at least one side or diagonal length of 500 mm or more.

[0015] In the following, the direction in which the mask MSK and plate P are driven during scanning exposure (scanning direction) is referred to as the X-axis direction, the direction in the horizontal plane perpendicular to this is referred to as the Y-axis direction, the direction perpendicular to the X-axis and Y-axis is referred to as the Z-axis direction, and the rotation (tilt) directions around the X-axis, Y-axis, and Z-axis are referred to as the θx, θy, and θz directions, respectively.

[0016] The exposure apparatus 10 includes an illumination system IOP, a mask stage MST that holds a mask MSK, a projection optical system PL, a body 70 that supports these, a substrate stage PST that holds a plate P, and a control system for these. The control system provides overall control of each component of the exposure apparatus 10.

[0017] The body 70 includes a base (vibration isolation table) 71, columns 72A and 72B, an optical surface plate 73, a support 74, and a slide guide 75. The base (vibration isolation table) 71 is placed on a floor F and supports the columns 72A, 72B, etc., while isolating vibrations from the floor F. The columns 72A and 72B each have a frame shape, with the column 72A being placed inside the column 72B. The optical surface plate 73 has a flat plate shape and is fixed to the ceiling of the column 72A. The support 74 is supported by the ceiling of the column 72B via a slide guide 75. The slide guide 75 includes an air ball lifter and a positioning mechanism, and positions the support 74 (i.e., the mask stage MST, described later) at an appropriate position in the X-axis direction relative to the optical surface plate 73.

[0018] The illumination system IOP is disposed above the body 70. The illumination system IOP irradiates the mask MSK with illumination light IL. The detailed configuration of the illumination system IOP will be described later.

[0019] The mask stage MST is supported by a support 74. A mask MSK having a pattern surface (the lower surface in FIG. 1 ) on which a circuit pattern is formed is fixed to the mask stage MST by, for example, vacuum suction (or electrostatic suction). The mask stage MST is driven by a drive system including, for example, a linear motor at a predetermined stroke in the scanning direction (X-axis direction), and is also driven slightly in the non-scanning directions (Y-axis direction and θz direction).

[0020] Position information of the mask stage MST in the XY plane (including rotation information in the θz direction) is measured by an interferometer system. The interferometer system measures the position of the mask stage MST by irradiating a measurement beam onto a movable mirror (or a mirror-finished reflective surface (not shown)) provided at the end of the mask stage MST and receiving the light reflected from the movable mirror. The measurement results are supplied to a control device (not shown), which drives the mask stage MST via a drive system in accordance with the measurement results of the interferometer system.

[0021] The projection optical system PL is supported on an optical surface plate 73 below (on the -Z side of) the mask stage MST. The projection optical system PL is configured similarly to the projection optical system disclosed in, for example, U.S. Pat. No. 5,729,331. The projection optical system PL includes multiple (e.g., seven) projection optical units 100 (multi-lens projection optical units) arranged, for example, in a staggered pattern, to project the pattern image of the mask MSK. This forms a rectangular image field with the Y-axis direction as its longitudinal direction. Here, four projection optical units 100 are arranged at predetermined intervals in the Y-axis direction, and the remaining three projection optical units 100 are arranged at predetermined intervals in the Y-axis direction, spaced apart from the four projection optical units 100 on the +X side. Each of the multiple projection optical units 100 is, for example, a bilaterally telecentric, 1x1 system that forms an erect, normal image. The multiple projection areas of the staggered projection optical units 100 are collectively referred to as the exposure area.

[0022] When an illumination area on the mask MSK is illuminated by illumination light IL from the illumination system IOP, the illumination light IL that has passed through the mask MSK forms a projected image (partial erect image) of the circuit pattern of the mask MSK within that illumination area, via the projection optical system PL, in an irradiation area (exposure area (conjugate to the illumination area)) on a plate P arranged on the image plane side of the projection optical system PL. Here, a resist (sensitizer) is applied to the surface of the plate P. By synchronously driving the mask stage MST and the substrate stage PST, i.e., by driving the mask MSK in the scanning direction (X-axis direction) relative to the illumination area (illumination light IL) and driving the plate P in the same scanning direction relative to the exposure area (illumination light IL), the plate P is exposed and the pattern of the mask MSK is transferred onto the plate P.

[0023] The substrate stage PST is placed on a base (vibration isolation table) 71 below (on the -Z side of) the projection optical system PL. A plate P is held on the substrate stage PST via a substrate holder (not shown).

[0024] Position information of the substrate stage PST in the XY plane (including rotation information (yawing amount (rotation amount θz in the θz direction), pitching amount (rotation amount θx in the θx direction), and rolling amount (rotation amount θy in the θy direction))) is measured by an interferometer system. The interferometer system measures the position of the substrate stage PST by irradiating a measurement beam from the optical surface plate 73 onto a movable mirror (or a mirror-finished reflective surface (not shown)) provided at the end of the substrate stage PST, and receiving the reflected light from the movable mirror. The measurement results are supplied to a control device (not shown), and the control device drives the substrate stage PST in accordance with the measurement results of the interferometer system.

[0025] In exposure apparatus 10, alignment measurement (e.g., EGA, etc.) is performed prior to exposure, and the plate P is exposed using the results in the following procedure. First, in accordance with instructions from the control device, the mask stage MST and substrate stage PST are synchronously driven in the X-axis direction. This performs scanning exposure on the first shot area on plate P. When scanning exposure on the first shot area is completed, the control device moves (steps) the substrate stage PST to a position corresponding to the second shot area. Then, scanning exposure is performed on the second shot area. In the same manner, the control device repeats stepping between shot areas of plate P and scanning exposure on the shot areas to transfer the pattern of the mask MSK to all shot areas on plate P.

[0026] (Configuration of illumination system IOP) Next, the configuration of illumination system IOP in this embodiment will be described. Illumination system IOP includes a plurality of illumination units 90 corresponding to the plurality of projection optical units 100 included in projection optical system PL. Figure 2 is a diagram schematically showing the configuration of illumination unit 90.

[0027] The illumination unit 90 includes a first light source unit OPU1, a second light source unit OPU2, and an illumination optical system 80.

[0028] (Configuration of light source unit) The first light source unit OPU1 includes a heat sink 40, a first light source array 20A, and a first magnifying optical system 30A, and the second light source unit OPU2 includes a heat sink 40, a second light source array 20B, and a second magnifying optical system 30B.

[0029] Fig. 3(A) is a plan view schematically showing the configuration of the heat sink 40, and Fig. 3(B) is a cross-sectional view taken along line A-A in Fig. 3(A). In this embodiment, the heat sink 40 has a rectangular planar shape. In the following description, the longitudinal direction of the heat sink 40 is defined as the X1 direction, the lateral direction as the Y1 direction, and the thickness direction as the Z1 direction. The X1 direction, Y1 direction, and Z1 direction are perpendicular to one another.

[0030] In this embodiment, the heat sink 40 is a microchannel heat sink made of metal such as copper and having a thickness of 7 mm or less.

[0031] The heat sink 40 has a flow path 402 through which a coolant flows, a coolant inlet 403 that supplies the coolant to the flow path 402, and a coolant outlet 404 that discharges the coolant that has passed through the flow path 402. In Fig. 3A, the flow path 402 is indicated by a dotted line. In this embodiment, the flow path 402 meanders inside the heat sink 40.

[0032] As shown in FIG. 3B , the heat sink 40 has a first surface 40a and a second surface 40b facing each other. The first surface 40a has a plurality of protrusions 401 formed thereon, protruding from the first surface 40a and extending in the Y1 direction. In this embodiment, each of the protrusions 401 is a part of the heat sink 40. That is, the protrusions 401 are made of a metal such as copper. The protrusions 401 can be formed, for example, by etching the first surface 40a of the heat sink 40 using a resist pattern formed by a photolithography process as a mask. The protrusions 401 may also be formed by machining the first surface 40a of the heat sink 40.

[0033] An insulating layer 41 and a wiring layer 42 are formed in this order on the first surface 40a on both sides in the X1 direction of each protrusion 401. The insulating layer 41 is made of an insulating material such as prepreg, and the wiring layer 42 is made of a metal foil such as copper foil.

[0034] Fig. 4(A) is a plan view schematically showing the state in which the first light source array 20A and the second light source array 20B are mounted on the heat sink 40, Fig. 4(B) is a cross-sectional view taken along line A-A in Fig. 4(A), and Fig. 4(C) is an enlarged view of the portion surrounded by the circle C1 in Fig. 4(B). Fig. 5(A) is a further enlarged view of the portion surrounded by the circle C1 in Fig. 4(B). Note that hatching of LED chips 23A and 23B, which will be described later, is omitted in Figs. 4(B), 4(C), and 5(A).

[0035] 4A, the first light source array 20A includes a plurality of LED (Light Emitting Diode) chips 23A (5×5 in FIG. 4A) arranged two-dimensionally on the first surface 40a of the heat sink 40. The number of LED chips 23A may be changed as needed.

[0036] Each LED chip 23A is arranged so as to overlap, in plan view, one of the plurality of protrusions 401. In other words, each protrusion 401 overlaps, in plan view, with at least one of the plurality of LED chips 23A.

[0037] 5A, each LED chip 23A has a light-emitting portion 231A, a package substrate 232 for holding the light-emitting portion 231A, an anode electrode 233, and a cathode electrode 234. The package substrate 232 is made of, for example, ceramic such as aluminum nitride, which has electrical insulation properties and high thermal conductivity.

[0038] As shown in FIGS. 4C and 5A, each LED chip 23A is connected to the protrusion 401 and the wiring layer 42 via solder 44. As shown in FIG. 5A, in this embodiment, the sum of the thickness (height) H1 of the insulating layer 41 and the thickness (height) H2 of the wiring layer 42 is equal to the height H3 of the protrusion 401. That is, the distance from the upper surface of the protrusion 401 to the first surface 40a is equal to the distance from the upper surface of the wiring layer 42 to the first surface 40a. In other words, the surface of the protrusion 401 facing the LED chip 23A and the surface of the wiring layer 42 facing the LED chip 23A are coplanar. This improves adhesion between the LED chip 23A and the wiring layer 42 and the protrusion 401. The sum of the thickness H1 of the insulating layer 41 and the thickness H2 of the wiring layer 42 does not have to be exactly the same as the height H3 of the protrusion 401, and the sum of the thickness H1 of the insulating layer 41 and the thickness H2 of the wiring layer 42 may differ from the height H3 of the protrusion 401 by an amount equivalent to a manufacturing error.

[0039] In this embodiment, the LED chips 23A adjacent to each other in the X1 direction are connected in series by the wiring layer 42, and as shown by the arrow AR1 in FIG. 4B, a current flows through the wiring layer 42 and the LED chips 23A in, for example, the −X1 direction.

[0040] 5B is an equivalent circuit diagram of the first light source unit OPU1 and the second light source unit OPU2 according to the first embodiment. The LED chips 23A connected in series by the wiring layer 42 are connected to the control board 26 via the connector 25, as shown in FIG. 5B. The control board 26 controls the value of the current supplied to the LED chips 23A, etc.

[0041] As shown in FIG. 4A, the LED chips 23A are arranged at a pitch P1, which is the distance between the centers of adjacent LED chips 23A.

[0042] As described above, each of the multiple LED chips 23A has a light-emitting portion 231A, and the peak wavelength of the light emitted from the light-emitting portion 231A is in the range of 380 to 390 nm. In other words, the light-emitting portion 231A is an ultraviolet LED (UV LED). It is more preferable that the peak wavelength of the light emitted from the light-emitting portion 231A is 385 nm. The light-emitting surface of the light-emitting portion 231A is square, and the length of one side is a1. The Z1 direction is approximately parallel to the optical axis of the light emitted by the light-emitting portion 231A.

[0043] The second light source array 20B includes a plurality of LED chips 23B (5×5 in FIG. 4A ) arranged two-dimensionally on the first surface 40a of the heat sink 40. The number of LED chips 23B may be changed as needed.

[0044] Each LED chip 23B is arranged so as to overlap, in plan view, one of the plurality of protrusions 401. In other words, each protrusion 401 overlaps, in plan view, with at least one of the plurality of LED chips 23B.

[0045] As shown in FIG. 5A, each LED chip 23B has a light-emitting portion 231B, a package substrate 232 for holding the light-emitting portion 231B, an anode electrode 233, and a cathode electrode 234.

[0046] As shown in FIG. 4C, each LED chip 23B is connected to the protrusion 401 and the wiring layer 42 via solder 44. As shown in FIG. 5A, in this embodiment, the sum of the thickness (height) H1 of the insulating layer 41 and the thickness (height) H2 of the wiring layer 42 is equal to the height H3 of the protrusion 401. That is, the distance from the top surface of the protrusion 401 to the first surface 40a is equal to the distance from the top surface of the wiring layer 42 to the first surface 40a. This improves adhesion between the LED chip 23B and the wiring layer 42 and the protrusion 401. In this embodiment, adjacent LED chips 23B in the X1 direction are connected in series by the wiring layer 42. As shown by arrow AR1 in FIG. 4B, current flows through the wiring layer 42 and the LED chip 23B in, for example, the −X1 direction. As shown in FIG. 5B, the LED chips 23B connected in series by the wiring layer 42 are connected to the control board 26 via the connector 25. The control board 26 controls the value of the current supplied to the LED chip 23B.

[0047] 4A, the LED chips 23B are arranged at a pitch P2, which is the distance between the centers of adjacent LED chips 23B. The arrangement pitch P1 of the LED chips 23A and the arrangement pitch P2 of the LED chips 23B may be the same as or different from each other.

[0048] As described above, each of the multiple LED chips 23B has a light-emitting portion 231B, and the peak wavelength of the light emitted from the light-emitting portion 231B is in the range of 360 to 370 nm. In other words, the light-emitting portion 231B is a UV LED. It is more preferable that the peak wavelength of the light emitted from the light-emitting portion 231B is 365 nm. The light-emitting surface of the light-emitting portion 231B is square, and the length of one side is a2. The length a2 of one side of the light-emitting surface of the light-emitting portion 231B may be the same as or different from the length a1 of one side of the light-emitting surface of the light-emitting portion 231A.

[0049] The luminance of light from the light-emitting portion 231A of the LED chip 23A and the luminance of light from the light-emitting portion 231B of the LED chip 23B decrease as the temperatures of the LED chips 23A and 23B increase. In other words, the light-emitting efficiency of the LED chips 23A and 23B decreases as the temperatures increase.

[0050] In this embodiment, as shown in FIG. 4B , the LED chips 23A are mounted directly on the heat sink 40. This allows the LED chips 23A to be cooled more efficiently than when the LED chips 23A are arranged on, for example, a substrate and the substrate on which the LED chips 23A are arranged is mounted on a heat sink. This prevents a decrease in the brightness of the light emitted from the first light source array 20A. Furthermore, the size of the first light source unit OPU1 in the Z1 direction can be reduced compared to when the substrate on which the LED chips 23A are arranged is mounted on a heat sink.

[0051] Similarly, because the LED chips 23B are mounted directly on the heat sink 40, the LED chips 23B can be cooled more efficiently than when a substrate on which the LED chips 23B are arranged is mounted on a heat sink. This makes it possible to suppress a decrease in the brightness of the light emitted from the second light source array 20B. Furthermore, the size of the second light source unit OPU2 in the Z1 direction can be reduced.

[0052] Next, the first magnifying optical system 30A and the second magnifying optical system 30B will be described. Fig. 6 is a diagram for explaining the first magnifying optical system 30A and the second magnifying optical system 30B provided in the first light source unit OPU1 and the second light source unit OPU2, respectively.

[0053] As shown in FIG. 6 , the first magnifying optical system 30A is a magnifying optical system for forming a magnified image of the light-emitting portion 231A of each LED chip 23A on a predetermined plane PP. The first magnifying optical system 30A includes a plurality of lens units 31A arranged to correspond to the arrangement of the LED chips 23A. Each lens unit 31A is a double-telecentric optical system that magnifies and projects the light-emitting portion 231A at a magnification M1 equal to or greater than (the arrangement pitch P1 of the LED chips 23B) / (the length a1 of one side of the light-emitting surface of the light-emitting portion 231A). For clarity of illustration, FIG. 6 shows only four LED chips 23A (23B) arranged in a row along the Y1 direction.

[0054] The second magnifying optical system 30B is an optical system for forming a magnified image of the light-emitting portion 231B of each LED chip 23B on a predetermined plane PP. The second magnifying optical system 30B includes a plurality of lens units 31B arranged to correspond to the arrangement of the LED chips 23B. Each of the lens units 31B is a double-telecentric optical system that magnifies and projects the light-emitting portion 231B at a magnification M2 that is equal to or greater than (the arrangement pitch P2 of the LED chips 23A) / (the length a2 of one side of the light-emitting surface of the light-emitting portion 231B).

[0055] In this embodiment, each of the lens units 31A and 31B includes four plano-convex lenses, but this is not limiting, and the lens units 31A and 31B may include, for example, two biconvex lenses, three biconvex lenses, or a plano-convex lens and a biconvex lens.

[0056] (Configuration of illumination optical system 80) Returning to Figure 2, the illumination optical system 80 includes a first focusing optical system 81A including a first dichroic mirror DM1, a second focusing optical system 81B, a second dichroic mirror DM2, an imaging optical system 83, a fly's eye lens FEL, and a condenser optical system 84.

[0057] The first focusing optical system 81A forms a pupil of the magnified image of the light-emitting unit 231A formed by the first magnifying optical system 30A. That is, the rear focal position of the first focusing optical system 81A is the pupil position. The first focusing optical system 81A has a first dichroic mirror DM1 along the optical path, which reflects at least a portion of the light with a peak wavelength of 385 nm. This causes the light beam to be incident on the second dichroic mirror DM2. Note that the first focusing optical system 81A may be configured without the first dichroic mirror DM1. In this case, the arrangement of the first light source unit OPU1 and the arrangement of each lens in the first focusing optical system 81A may be appropriately adjusted so that the light beam is incident on the second dichroic mirror DM2. Furthermore, the first focusing optical system 81A may be configured with a single lens or a lens group including multiple lenses.

[0058] The second focusing optical system 81B forms a pupil of the magnified image of the light-emitting unit 231B formed by the second magnifying optical system 30B. That is, the rear focal position of the second focusing optical system 81B is the pupil position. The second focusing optical system 81B may be composed of a single lens or a lens group including multiple lenses.

[0059] The second dichroic mirror DM2 transmits at least a portion of the light with a peak wavelength of 385 nm and reflects at least a portion of the light with a peak wavelength of 365 nm, thereby forming a composite image by superimposing the pupil image formed by the first focusing optical system 81A and the pupil image formed by the second focusing optical system 81B.

[0060] In this embodiment, the second dichroic mirror DM2 forms a composite image by superimposing the pupil image formed by the first focusing optical system 81A and the pupil image formed by the second focusing optical system 81B. That is, the second dichroic mirror DM2 is disposed at a position that is the back focal position of the first focusing optical system 81A and the back focal position of the second focusing optical system 81B. As a result, the second dichroic mirror DM2 Koehler-illuminates the light emitted from the first light source unit OPU1 and the light emitted from the second light source unit OPU2. By Koehler-illuminating the light, it is possible to reduce changes in the illuminance of the light beam of the pupil image formed by the first focusing optical system 81A and the second focusing optical system 81B. In addition, without being limited to the configuration of this embodiment, the first focusing optical system 81A and the second focusing optical system 81B may be configured to perform critical illumination that forms an image of the first light source unit OPU1 and an image of the second light source unit OPU2 on the second dichroic mirror DM2, respectively.

[0061] The illumination unit 90 is provided with a detector DT10 for monitoring light with a peak wavelength of 385 nm, a detector DT20 for monitoring light with a peak wavelength of 365 nm, and a detector DT30 for monitoring light with a peak wavelength of 385 nm and light with a peak wavelength of 365 nm.

[0062] Specifically, detector DT10 detects the illuminance of light with a peak wavelength of 385 nm reflected by first dichroic mirror DM1. Detector DT20 detects the illuminance of light with a peak wavelength of 365 nm reflected by second dichroic mirror DM2. Detector DT30 detects the illuminance of 385 nm light unintentionally reflected by second dichroic mirror DM2 and the illuminance of 365 nm light unintentionally transmitted by second dichroic mirror DM2.

[0063] The detection results of detectors DT10 to DT30 are output to a control board 26, and the control board 26 controls the value of the current supplied to the LED chips 23A and 23B provided in the first light source unit OPU1 and the second light source unit OPU2, respectively, based on the detection results of detectors DT10 to DT30.

[0064] The imaging optical system 83 is a double-telecentric optical system that projects the composite image formed by the second dichroic mirror DM2 onto the incident end of the fly-eye lens FEL at an equal magnification. Note that the imaging optical system 83 may also reduce and project the composite image formed by the second dichroic mirror DM2 onto the incident end of the fly-eye lens FEL.

[0065] The fly-eye lens FEL is formed by closely arranging a large number of lens elements, each having a positive refractive power, in a row and column so that their optical axes are parallel to the reference optical axis AX. Each lens element constituting the fly-eye lens FEL has a rectangular cross section similar to the shape of the illumination field to be formed on the mask MSK (and consequently the shape of the exposure area to be formed on the plate P).

[0066] Therefore, the light beam incident on the fly-eye lens FEL is wavefront split by the multiple lens elements, and one light source image is formed on or near the rear focal plane (exit surface) of each lens element. That is, a substantial surface light source, i.e., a secondary light source, consisting of multiple light source images is formed on or near the rear focal plane (exit surface) of the fly-eye lens FEL. The light beam from the secondary light source formed on or near the rear focal plane (exit surface) of the fly-eye lens FEL is incident on an aperture stop 85 arranged nearby. Note that in this embodiment, the rear focal plane (exit surface) of the fly-eye lens FEL is optically conjugate with the first light source array 20A and the second light source array 20B.

[0067] The aperture stop 85 is disposed at a position that is nearly optically conjugate with the entrance pupil plane of the projection optical system PL, and has a variable opening for defining the range that contributes to illumination from the secondary light source. The aperture stop 85 changes the aperture diameter of the variable opening to set the σ value (the ratio of the aperture diameter of the secondary light source image on the pupil plane of the projection optical system to the aperture diameter of the pupil plane) that determines the illumination conditions to a desired value. The light from the secondary light source that passes through the aperture stop 85 is subjected to the focusing action of the condenser optical system 84, and then illuminates a mask MSK on which a predetermined pattern is formed in a superimposed manner.

[0068] The wavelengths of the light emitted by the first light source unit OPU1 and the second light source unit OPU2 are not limited to those described above, and the first light source unit OPU1 and the second light source unit OPU2 may be constructed by appropriately combining LED chips that emit light having a peak wavelength in the range of 360 to 440 nm.

[0069] For example, the peak wavelength of the light emitted from the light-emitting portion 231A of the LED chip 23A may be in the range of 400 to 410 nm. For example, the first light source unit OPU1 may be configured to emit light with a peak wavelength of 405 nm, and the second light source unit OPU2 may be configured to emit light with a peak wavelength of 365 nm. Alternatively, the first light source unit OPU1 may be configured to emit light with a peak wavelength of 395 nm, and the second light source unit OPU2 may be configured to emit light with a peak wavelength of 385 nm. The combination of the wavelengths of the light emitted from the first light source unit OPU1 and the second light source unit OPU2 is not limited to these examples. Note that, when the combination of the wavelengths of the light emitted from the first light source unit OPU1 and the second light source unit OPU2 is a combination other than that of the first embodiment, it is preferable to change the material of the dichroic mirror appropriately depending on the wavelengths used.

[0070] As described above in detail, the first light source unit OPU1 includes a heat sink 40 and a plurality of LED chips 23A arranged two-dimensionally on the first surface 40a of the heat sink 40. The first surface 40a of the heat sink 40 has a plurality of protrusions 401 formed thereon, protruding from the first surface 40a and overlapping with at least one of the plurality of LED chips 23A in a plan view. This allows the LED chips 23A to be mounted directly on the heat sink 40, thereby enabling the LED chips 23A to be cooled more efficiently than when a substrate on which the LED chips 23A are arranged is mounted on a heat sink. This reduces a decrease in the brightness of the light emitted from the first light source unit OPU1. Furthermore, the size of the first light source unit OPU1 in the Z1 direction can be reduced compared to when a substrate on which the LED chips 23A are arranged is mounted on a heat sink.

[0071] In the first embodiment, the protrusion 401 extends in the Y1 direction, but the protrusion 401 may extend in the X1 direction. When the protrusion 401 extends in the X1 direction, the LED chips 23A adjacent to each other in the Y1 direction are connected in series, and the LED chips 23B adjacent to each other in the Y1 direction are connected in series.

[0072] (Variant 1) Figure 7(A) is a plan view showing a heat sink 40A according to variant 1 of the first embodiment, and Figure 7(B) is a plan view showing the state in which a first light source array 20A and a second light source array 20B are mounted on the heat sink 40A according to variant 1.

[0073] 7A, the heat sink 40A has a plurality of spaced apart protrusions (posts) 401A on the first surface 40a. The protrusions 401A overlap the LED chips 23A in plan view.

[0074] In the first modification, the protrusion 401A has a circular planar shape, but the planar shape of the protrusion 401A may be an ellipse or a polygonal shape such as a square or a pentagon. The other configurations are the same as those in the first embodiment, and therefore detailed description thereof will be omitted.

[0075] The LED chip 23A may be mounted directly on the heat sink 40A using the protrusions 401A spaced apart from each other as in Modification 1. This allows the LED chip 23A to be cooled more efficiently and the size of the first light source unit OPU1 in the Z1 direction to be reduced compared to when a substrate on which a plurality of LED chips 23A are arranged is mounted on a heat sink.

[0076] (Variant 2) Figure 8(A) is a plan view showing a heat sink 40B according to variant 2 of the first embodiment, and Figure 8(B) is a plan view showing the state in which the first light source array 20A and the second light source array 20B are mounted on the heat sink 40B according to variant 2.

[0077] As shown in Figure 8 (A), the heat sink 40B has, on the first surface 40a, a plurality of protrusions (posts) 401A that protrude from the first surface 40a and are spaced apart from each other, and a plurality of protrusions 401 that protrude from the first surface 40a and extend in the Y1 direction.

[0078] The plurality of protrusions 401A overlap with the plurality of LED chips 23A in a planar view. The protrusions 401 overlap with the plurality of LED chips 23A in a planar view. In FIG. 8A, the protrusions 401A and the protrusions 401 are alternately arranged in the X1 direction, but the arrangement of the protrusions 401A and the protrusions 401 is not limited to that shown in FIG. 8A. For example, the plurality of protrusions 401A may be arranged together on the +X1 side, and the plurality of protrusions 401 may be arranged together on the −X1 side. Furthermore, the number of protrusions 401 may be one, or three or more. The other configurations are the same as those of the first embodiment, and therefore detailed description thereof will be omitted.

[0079] As in the second modification, a protrusion 401A overlapping each of the plurality of LED chips 23A in a plan view and a protrusion 401 overlapping each of the plurality of LED chips 23A in a plan view may be combined.

[0080] In the second modification, the protrusion 401 extends in the Y1 direction, but may extend in the X1 direction, in which case the LED chips 23A adjacent to each other in the Y1 direction are connected in series.

[0081] Second Embodiment FIG. 9A is a plan view illustrating a heat sink 40C according to a second embodiment, and FIG. 9B is a cross-sectional view taken along line AA of FIG. 9A.

[0082] The heat sink 40C extends in the X1 direction and has a flow path 402A through which a refrigerant flows from a refrigerant inlet 403A provided at one end of the heat sink 40C in the X1 direction to a refrigerant outlet 404A provided at the other end of the heat sink 40C in the X1 direction.

[0083] In this embodiment, the heat sink 40C has a plurality of flow paths 402A corresponding to the respective rows of the LED chips 23A, but one flow path 402A may be provided for each of the plurality of rows of the LED chips 23A.

[0084] The heat sink 40C has five protrusions 401 on the first surface 40a, protruding from the first surface 40a, extending in the Y1 direction, and spaced apart in the X1 direction. The five protrusions 401 are referred to as protrusions 401a, 401b, 401c, 401d, and 401e, starting from the end where the refrigerant inlet 403A is provided. If the widths in the X1 direction of the protrusions 401a, 401b, 401c, 401d, and 401e are Wa, Wb, Wc, Wd, and We, respectively, the relationship Wa<Wb<Wc<Wd<We holds. That is, in the second embodiment, the widths in the X1 direction of the protrusions 401 narrower the closer they are to the refrigerant inlet 403A.

[0085] As shown by arrow AR2 in Figure 9 (B) , the refrigerant flows through flow path 402A in the -X1 direction, so the cooling effect of the refrigerant on LED chip 23A is higher the closer it is to refrigerant inlet 403A. On the other hand, the closer the protrusion 401 is to refrigerant inlet 403A, the narrower its width in the X1 direction, and therefore the cooling effect of the protrusion 401 on LED chip 23A is lower the closer it is to refrigerant inlet 403A. Therefore, by arranging protrusion 401 with a narrow width in the X1 direction and a low cooling effect near refrigerant inlet 403A, where the refrigerant has a high cooling effect on LED chip 23A, and arranging protrusion 401 with a wide width in the X1 direction and a high cooling effect near refrigerant outlet 404A, where the refrigerant has a low cooling effect on LED chip 23A, uneven cooling of the LED chip 23A is reduced, and the LED chip 23A can be cooled approximately uniformly.

[0086] (Modification 1) FIG. 10A is a plan view illustrating a heat sink 40D according to Modification 1 of the second embodiment, and FIG. 10B is a cross-sectional view taken along line AA of FIG. 10A.

[0087] In the first modification, protrusions 401A are provided on the first surface 40a of the heat sink 40D. The protrusions 401A protrude from the first surface 40a and overlap the LED chips 23A in a plan view. In the first modification, the planar shape of the protrusions 401A is assumed to be square.

[0088] As shown in Figures 10A and 10B, the protrusions 401A closest to the refrigerant inlet 403A are designated as protrusions 401Aa, and the protrusions 401A are designated as protrusions 401Ab, 401Ac, 401Ad, and 401Ae in order in the -X direction. If the lengths of one side of the protrusions 401Aa, 401Ab, 401Ac, 401Ad, and 401Ae are La, Lb, Lc, Ld, and Le, respectively, then La < Lb < Lc < Ld < Le. Therefore, in Modification 1, the area of ​​the top surface of the protrusions 401A decreases toward the end where the refrigerant inlet 403A is provided. The remaining configuration is the same as in the second embodiment, and detailed description thereof will be omitted.

[0089] As shown by arrow AR2 in FIG. 10B , the refrigerant flows through the flow path 402A in the −X1 direction, so the cooling effect of the refrigerant on the LED chip 23A is greater the closer it is to the refrigerant inlet 403A. On the other hand, the closer the protrusion 401A is to the refrigerant inlet 403A, the smaller its top surface area is, so the cooling effect of the protrusion 401A on the LED chip 23A is lower the closer it is to the refrigerant inlet 403A. Therefore, by arranging the protrusion 401A with a small top surface area and low cooling effect near the refrigerant inlet 403A, where the refrigerant has a high cooling effect on the LED chip 23A, and by arranging the protrusion 401A with a large top surface area and high cooling effect near the refrigerant outlet 404A, where the refrigerant has a low cooling effect on the LED chip 23A, uneven cooling of the LED chip 23A is reduced, enabling the LED chip 23A to be cooled substantially uniformly. The planar shape of the protrusion 401A may be circular or another shape.

[0090] (Modification 2) FIG. 11A is a plan view illustrating a heat sink 40E according to Modification 2 of the second embodiment, and FIG. 11B is a cross-sectional view taken along line AA of FIG. 11A.

[0091] As shown in Figure 11 (A), the heat sink 40E has, on the first surface 40a, protrusions (posts) 401A that overlap with each of the multiple LED chips 23A in a planar view, and protrusions 401 that extend in the Y1 direction and overlap with each of the multiple LED chips 23A in a planar view.

[0092] The protrusion 401A has a square planar shape with a side length of L. The width of the protrusion 401 in the X1 direction is W. In this embodiment, the length L of one side of the protrusion 401A is equal to the width W of the protrusion 401 in the X1 direction. Therefore, the area of ​​the top surface of the protrusion 401A is smaller than the area of ​​the top surface of the protrusion 401.

[0093] The protrusion 401A and the protrusion 401 are provided in this order from one end where the refrigerant inlet 403A is provided to the other end where the refrigerant outlet 404A is provided. The other configurations are the same as those of the second embodiment, so detailed description will be omitted.

[0094] As described above, the area of ​​the upper surface of protrusion 401A is smaller than the area of ​​the upper surface of protrusion 401. Therefore, the cooling effect of protrusion 401A on LED chip 23A is lower than the cooling effect of protrusion 401 on LED chip 23A. On the other hand, as shown by arrow AR2 in Figure 11(B) , the refrigerant flows in the -X1 direction within flow path 402A, and therefore the cooling effect of the refrigerant on LED chip 23A is higher the closer to refrigerant inlet 403A.

[0095] Therefore, by arranging the protrusion 401A, which has a small upper surface area and a low cooling effect, near the refrigerant inlet 403A, where the refrigerant has a high cooling effect on the LED chip 23A, and by arranging the protrusion 401, which has a large upper surface area and a high cooling effect, near the refrigerant outlet 404A, where the refrigerant has a low cooling effect on the LED chip 23A, it is possible to reduce uneven cooling of the LED chip 23A and to cool the LED chip 23A approximately uniformly. Note that the planar shape of the protrusion 401A may be other shapes, such as a circular shape.

[0096] Third Embodiment Fig. 12 is a cross-sectional view illustrating a heat sink 40F according to a third embodiment. As shown in Fig. 12, the heat sink 40F has an internal space 410 and a working fluid 411 held in the internal space 410. The internal space 410 is disposed between the first surface 40a and the flow path 402A. That is, in the heat sink 40F, a vapor chamber is formed between the first surface 40a and the flow path 402A.

[0097] The working fluid 411 held in the internal space 410 evaporates due to the heat from the LED chip 23A. The evaporated working fluid 411 moves within the internal space 410 as indicated by arrow AR3, thereby diffusing the heat. The diffused working fluid 411 is cooled and liquefied by the refrigerant flowing through the flow path 402A. In this way, the working fluid 411 repeatedly evaporates and liquefies, thereby cooling the heat source (LED chips 23A and 23B).

[0098] The vapor chamber has high thermal conductivity and is planar, allowing heat to be diffused instantly over a wide area, allowing the heat sink 40F to cool the LED chip 23A more efficiently than a heat sink without a vapor chamber.

[0099] The other configurations are the same as those of the heat sink 40C according to the second embodiment, and therefore detailed description thereof will be omitted. Note that the heat sinks 40, 40A to 40E according to the first and second embodiments and their modified examples may have a vapor chamber.

[0100] 13 is a diagram showing a preferable configuration of a lighting unit 90A when using a heat sink 40F according to the third embodiment. When LED chips are directly mounted on a heat sink equipped with a vapor chamber, it is preferable that the light-emitting surfaces of the light-emitting portions 231A and 231B of the LED chips 23A and 23B face the direction of gravity, as shown in FIG. 13 , so that the liquefied working fluid 411 moves toward the LED chips 23A and 23B due to gravity.

[0101] Therefore, the illumination optical system 80A of the illumination unit 90A includes a third focusing optical system 81C, a fourth focusing optical system 81D including a third dichroic mirror DM3, a second dichroic mirror DM2, an imaging optical system 83, a fly's eye lens FEL, and a condenser optical system 84.

[0102] The third focusing optical system 81C forms a pupil of the enlarged image of the light-emitting unit 231A formed by the first magnifying optical system 30A. That is, the rear focal position of the third focusing optical system 81C is the pupil position. The arrangement of the first light source unit OPU1 and the arrangement of each lens of the third focusing optical system 81C are adjusted so that the light beam is incident on the second dichroic mirror DM2.

[0103] The fourth focusing optical system 81D forms a pupil of the magnified image of the light-emitting unit 231B formed by the second magnifying optical system 30B. That is, the rear focal position of the fourth focusing optical system 81D is the pupil position. The fourth focusing optical system 81D has a third dichroic mirror DM3 in the optical path, which reflects at least a portion of the light with a peak wavelength of 365 nm. This causes the light beam to be incident on the second dichroic mirror DM2.

[0104] The second dichroic mirror DM2, the imaging optical system 83, the fly-eye lens FEL, and the condenser optical system 84 have the same configurations and functions as those in FIG. 2, and therefore detailed description thereof will be omitted.

[0105] Fourth Embodiment In the first to third embodiments, the plurality of LED chips 23A and the plurality of LED chips 23B are connected in series by the wiring layer 42, but the plurality of LED chips 23A and the plurality of LED chips 23B may be connected in parallel by the wiring layer 42.

[0106] FIG. 14A is a plan view that schematically shows the configuration of a heat sink 40G according to the fourth embodiment, and FIG. 14B is a cross-sectional view taken along line AA of FIG. 14A.

[0107] 14A, a first surface 40a of the heat sink 40G is formed with a plurality of protruding portions 401 that protrude from the first surface 40a and extend in the Y1 direction. An insulating layer 41 and a wiring layer 42 are formed in this order on the first surface 40a on both sides in the X1 direction of each protruding portion 401. The insulating layer 41 and the wiring layer 42 extend in the Y1 direction.

[0108] 15(A) to 15(C) are plan views schematically showing a state in which the first light source array 20A and the second light source array 20B are mounted on a heat sink 40G, Fig. 15(B) is a cross-sectional view taken along line A-A in Fig. 15(A), and Fig. 15(C) is an enlarged view of the portion surrounded by an ellipse C1 in Fig. 15(B). Fig. 16 is an equivalent circuit diagram of the first and second light source units according to the fourth embodiment.

[0109] 15A, each protrusion 401 overlaps with at least one of the LED chips 23A in plan view. As shown in FIG. 15C, each LED chip 23A is connected to the protrusion 401 and the wiring layer 42 via solder 44.

[0110] 15(A) to 15(C), the anode electrodes 233 of the LED chips 23A adjacent to each other in the Y1 direction are electrically connected via a wiring layer 42 provided on the +X1 side of the protrusion 401. The cathode electrodes 234 of the LED chips 23A adjacent to each other in the Y1 direction are electrically connected via a wiring layer 42 provided on the −X1 side of the protrusion 401. As a result, the LED chips 23A adjacent to each other in the Y1 direction are connected in parallel via the wiring layer 42, as shown in FIG.

[0111] In this way, a plurality of LED chips 23A adjacent to each other in the Y1 direction may be connected in parallel. The same applies to a plurality of LED chips 23B. Since the other configurations are the same as those in the first embodiment, detailed description thereof will be omitted. Note that, in the fourth embodiment, a plurality of (two) wiring layers 42 are formed on one insulating layer 41 arranged between adjacent protrusions 401 in the X1 direction, but this is not limited to this. An insulating layer 41 may be provided corresponding to each of the plurality of (two) wiring layers 42 arranged between adjacent protrusions 401 in the X1 direction.

[0112] (Modification) FIG. 17A is a plan view that schematically shows the configuration of a heat sink 40H according to a modification of the fourth embodiment, and FIG. 17B is a cross-sectional view taken along line AA of FIG. 17A.

[0113] 17A, a first surface 40a of the heat sink 40H is formed with a plurality of protruding portions 401 that protrude from the first surface 40a and extend in the Y1 direction. An insulating layer 41 and a wiring layer 42 are formed in this order on the first surface 40a on the +X1 side of each protruding portion 401. The insulating layer 41 and the wiring layer 42 extend in the Y1 direction.

[0114] Fig. 18(A) is a plan view schematically showing a state in which a first light source array 20A and a second light source array 20B are mounted on a heat sink 40H according to a modification of the fourth embodiment, Fig. 18(B) is a cross-sectional view taken along line A-A in Fig. 18(A), Fig. 18(C) is an enlarged view of the portion surrounded by an ellipse C1 in Fig. 18(B), and Fig. 19 is an equivalent circuit diagram of the first and second light source units according to the modification of the fourth embodiment.

[0115] 18A, each protrusion 401 overlaps with at least one of the LED chips 23A in plan view. As shown in FIG. 18C, each LED chip 23A is connected to the protrusion 401 and the wiring layer 42 via solder 44.

[0116] 18A to 18C, the anode electrodes 233 of the LED chips 23A adjacent to each other in the Y1 direction are electrically connected via the wiring layer 42 provided on the +X1 side of the protrusion 401. The cathode electrodes 234 of the LED chips 23A adjacent to each other in the Y1 direction are electrically connected via the protrusion 401 and are connected to a reference potential via the protrusion 401. As a result, the LED chips 23A adjacent to each other in the Y1 direction are connected in parallel via the protrusion 401 and the wiring layer 42, as shown in FIG.

[0117] In this way, the LED chips 23A adjacent to each other in the Y1 direction may be connected in parallel. The same applies to the LED chips 23B. The other configurations are the same as those in the first embodiment, and therefore detailed description thereof will be omitted.

[0118] In the above embodiment and its modified examples, the first light source array 20A and the second light source array 20B are respectively mounted on the heat sinks 40, 40A to 40H having the same configuration, but this is not limited to this. The configuration of the heat sink on which the first light source array 20A is mounted may be different from the configuration of the heat sink on which the second light source array 20B is mounted. For example, the first light source array 20A may be mounted on the heat sink 40 according to the first embodiment, and the second light source array 20B may be mounted on the heat sink 40C according to the second embodiment.

[0119] In the above embodiment and its modified examples, the heat sink has flow paths 402, 402A through which the refrigerant flows, but this is not limited to this. The heat sink may be, for example, a fin-type heat sink. The heat sink does not have to be a microchannel heat sink. In the above embodiment and its modified examples, the refrigerant inlets 403, 403A and the refrigerant outlets 404, 404A are provided on the side surfaces of the heat sink, but they may be provided on the first surface 40a or the second surface 40b of the heat sink, respectively.

[0120] Furthermore, in the above embodiment and its modified examples, the thickness of the heat sink is 7 mm or less. However, in this specification, the thickness of the heat sink refers to the length from the upper surface of the protrusion 401 and / or protrusion 401A formed on the first surface 40a of the heat sink to the second surface 40b. For example, in an apparatus for forming a wiring layer on a substrate, the upper limit of the thickness of the substrate that can be loaded may be limited to approximately 7 mm, making it impossible to form a wiring layer on a thick substrate. However, by making the thickness of the heat sink 7 mm or less, it becomes easier to form a wiring layer on the heat sink. However, if there are no manufacturing limitations on the light source unit, the thickness of the heat sink may be 7 mm or more.

[0121] Furthermore, the length from the upper surface of the protrusion 401 and / or the protrusion 401A to the first surface 40a (height H3 of the protrusion 401 and / or the protrusion 401A) is preferably 500 μm or less, and more preferably 150 to 200 μm. For example, if the height H3 of the protrusion 401 and / or the protrusion 401A is 200 μm, the thickness (height) H1 of the insulating layer 41 may be 130 μm, and the thickness (height) H2 of the wiring layer 42 may be 70 μm. The thickness of the insulating layer 41 may be smaller than the thickness of the wiring layer 42.

[0122] In the above embodiment and its modified examples, the protrusions 401, 401A are described as being part of the heat sink, but this is not limiting. For example, the protrusions 401, 401A may be a component separate from the heat sink (a component separate from the heat sink) that contacts the first surface 40a of the heat sink. That is, the protrusions 401, 401A may be formed by fixing (soldering or adhering) a component separate from the heat sink to the first surface 40a. In this case, the protrusions 401, 401A may be formed from the same material as the heat sink or from a different material. Note that, if the protrusions 401, 401A are formed from a material different from the heat sink, the protrusions 401, 401A are preferably made of a metal with high thermal conductivity.

[0123] In the above embodiment and its modified examples, the illumination unit 90, 90A includes the first light source unit OPU1, the second light source unit OPU2, and the illumination optical system 80, 80A including the second dichroic mirror DM2. However, this is not limiting. For example, the illumination unit 90, 90A may include only one of the first light source unit OPU1 and the second light source unit OPU2. In this case, the illumination optical system 80, 80A may have any configuration as long as it can guide light emitted from the first light source unit OPU1 or the second light source unit OPU2 to the mask MSK.

[0124] In the first and fourth embodiments and their modifications, the flow path 402 has a serpentine shape, but the flow path 402A in the second embodiment may be applied to the first and fourth embodiments and their modifications. Also, the heat sinks 40G and 40H according to the fourth embodiment and their modifications may have the vapor chamber described in the third embodiment.

[0125] The light source unit described above has been described as being used in an exposure apparatus used in the manufacture of liquid crystal display devices (flat panel displays), but it may also be used as a light source unit in an exposure apparatus that exposes silicon wafers to light to manufacture semiconductor devices.

[0126] The above-described embodiment is a preferred example of the present invention, but the present invention is not limited to this and can be modified in various ways without departing from the spirit of the present invention.

[0127] 10 Exposure apparatus 20A First light source array 20B Second light source array 40a First surface 40b Second surface 23A, 23B LED chip 40, 40A, 40B, 40C, 40D, 40E, 40F, 40G, 40H Heat sink 80, 80A Illumination optical system 90, 90A Illumination unit 100 Projection optical unit 231A, 231B Light-emitting portion 233 Anode-side electrode 234 Cathode-side electrode 401, 401A Protrusion 402, 402A Flow path 403, 403A Coolant inlet 404, 404A Coolant outlet DM2 Second dichroic mirror MSK Mask OPU1 First light source unit OPU2 Second light source unit PL Projection optical system P Glass substrate

Claims

1. A heat sink; a plurality of light source elements arranged two-dimensionally on a first surface of the heat sink; Equipped with The first surface of the heat sink is provided with a plurality of protrusions that protrude from the first surface and overlap with at least one of the plurality of light source elements in a plan view. Light source unit.

2. The plurality of light source elements are a plurality of first light source elements arranged in a first direction; a plurality of second light source elements spaced apart from the plurality of first light source elements in a second direction perpendicular to the first direction and arranged in the first direction; Including, The plurality of protrusions are a first protrusion extending in the first direction and overlapping each of the plurality of first light source elements in a plan view; a second protrusion extending in the first direction and overlapping each of the second light source elements in a plan view; Including, The light source unit according to claim 1 .

3. Among the plurality of first light source elements and the plurality of second light source elements, the first light source elements and the second light source elements adjacent to each other in the second direction are connected in series. The light source unit according to claim 2 .

4. an insulating layer formed on the first surface of the heat sink; a wiring layer is formed on the insulating layer; a height of at least one of the plurality of protrusions is equal to a total thickness of the insulating layer and the wiring layer; The light source unit according to claim 1 .

5. An insulating layer is formed on the first surface of the heat sink, a wiring layer is formed on the insulating layer; a surface of at least one of the plurality of protrusions facing the light source element and a surface of the wiring layer facing the light source element are in the same plane; The light source unit according to claim 1 .

6. a plurality of insulating layers formed on the first surface of the heat sink; a plurality of wiring layers are formed on the plurality of insulating layers, the plurality of wiring layers extend in the first direction and include a first wiring layer and a second wiring layer provided on both sides of the first protruding portion in a plan view, cathode-side electrodes of the plurality of first light source elements adjacent to each other in the first direction are electrically connected via the first wiring layer; anode-side electrodes of the plurality of first light source elements adjacent to each other in the first direction are electrically connected via the second wiring layer; The light source unit according to claim 2 .

7. a plurality of insulating layers formed on the first surface of the heat sink; a plurality of wiring layers are formed on the plurality of insulating layers, the plurality of wiring layers include a third wiring layer extending in the first direction and provided between the first protruding portion and the second protruding portion in a plan view; cathode-side electrodes of the plurality of first light source elements adjacent to each other in the first direction are electrically connected via the first protrusions, anode-side electrodes of the plurality of first light source elements adjacent to each other in the first direction are electrically connected via the third wiring layer; The light source unit according to claim 2 .

8. the heat sink has a flow path extending in the second direction, through which a refrigerant flows from a refrigerant inlet provided at one end of the heat sink in the second direction to a refrigerant outlet provided at the other end of the heat sink in the second direction, the second protrusion and the first protrusion are provided in this order from the one end side toward the other end side, a width of the second protrusion in the second direction being smaller than a width of the first protrusion in the second direction; The light source unit according to any one of claims 2, 3, 6 and 7.

9. The plurality of protrusions are spaced apart from one another and are provided at positions overlapping the plurality of light source elements in a plan view. The light source unit according to claim 1 .

10. the heat sink has a flow path extending in a first direction, through which a refrigerant flows from a refrigerant inlet provided at one end of the heat sink in the first direction to a refrigerant outlet provided at the other end of the heat sink in the first direction, The area of ​​the upper surfaces of the plurality of protrusions is smaller as it approaches the one end side. The light source unit according to claim 9 .

11. The plurality of light source elements are a plurality of first light source elements arranged in a first direction; a plurality of second light source elements spaced apart from the plurality of first light source elements in a second direction perpendicular to the first direction and arranged in the first direction; Including, The plurality of protrusions are a first protrusion extending in the first direction and overlapping each of the plurality of first light source elements in a plan view; a plurality of second protrusions overlapping the plurality of second light source elements in a plan view; Including, The light source unit according to claim 1 .

12. the heat sink has a flow path extending in the second direction, through which a refrigerant flows from a refrigerant inlet provided at one end of the heat sink in the second direction to a refrigerant outlet provided at the other end of the heat sink in the second direction, a width of each of the second protrusions in the second direction is substantially the same as a width of the first protrusion in the second direction; The plurality of second protrusions and the first protrusion are provided in this order from the one end side toward the other end side. The light source unit according to claim 11.

13. The heat sink has an internal space and a working fluid held in the internal space. The light source unit according to any one of claims 1 to 7 and claims 9 to 12.

14. The plurality of protrusions are formed of a part of the heat sink. The light source unit according to any one of claims 1 to 7 and claims 9 to 12.

15. The heat sink is a microchannel heat sink. The light source unit according to any one of claims 1 to 7 and claims 9 to 12.

16. The plurality of light source elements are a plurality of LED elements. The light source unit according to any one of claims 1 to 7 and claims 9 to 12.

17. The peak wavelength of the light emitted from the plurality of light source elements is within a range of 360 to 370 nm. The light source unit according to any one of claims 1 to 7 and claims 9 to 12.

18. The peak wavelength of the light emitted from the plurality of light source elements is in the range of 380 to 390 nm. The light source unit according to any one of claims 1 to 7 and claims 9 to 12.

19. The peak wavelength of the light emitted from the plurality of light source elements is in the range of 400 to 410 nm. The light source unit according to any one of claims 1 to 7 and claims 9 to 12.

20. The light source unit is for use in an exposure device. The light source unit according to any one of claims 1 to 7 and claims 9 to 12.

21. a light source unit according to any one of claims 1 to 7 and claims 9 to 12; and an illumination optical system that guides the light emitted from the light source unit to an illuminated object; A lighting unit comprising:

22. a plurality of light source units according to any one of claims 1 to 7 and claims 9 to 12; an illumination optical system including a combining optical element that combines light beams emitted from the plurality of light source units, and that guides the combined light beam emitted from the combining optical element to an illuminated object; A lighting unit comprising:

23. The lighting unit according to claim 21, a projection optical system that projects a pattern image of a mask illuminated by the illumination unit onto a photosensitive substrate; An exposure apparatus comprising:

24. The photosensitive substrate has at least one side length or diagonal length of 500 mm or more.

24. The exposure apparatus according to claim 23.

25. An exposure method using the exposure apparatus according to claim 23, comprising: illuminating a mask with the illumination unit; projecting a pattern image of the mask onto a photosensitive substrate using the projection optical system; An exposure method comprising: