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

Abstract

The light source unit includes: a plurality of light source elements two-dimensionally arranged on a surface of a fixed object; and a protruding portion that protrudes from the object to be fixed and that is provided between each of the plurality of light source elements and at least one of the other light source elements adjacent to each of the plurality of light source elements, the end portion of the protruding portion being located at a position higher than the lower surface of each of the light source elements.

Description

Technical Field

[0001] The invention relates to a light source unit, a lighting unit, an exposure device, and an exposure method. Background Art

[0002] In recent years, liquid crystal display panels have been widely used as display elements for personal computers, televisions, etc. Liquid crystal display panels are manufactured by forming a circuit pattern of a thin film transistor on a plate (glass substrate) using a photolithography technique. As a device used in the photolithography process, an exposure device is used that projects and exposes the original pattern formed on the photomask onto the photoresist layer on the plate via a projection optical system (for example, Patent Document 1).

[0003] Generally, there is a demand for a high-brightness surface light source that can be applied to various optical devices including the above-mentioned exposure device.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-21712 Summary of the invention

[0007] According to the first disclosed aspect, the light source unit comprises: a plurality of light source elements two-dimensionally arranged on the surface of a fixed object; and a protrusion which protrudes from the fixed object and is arranged between each of the plurality of light source elements and at least one of the other light source elements adjacent to each of the light source elements, and an end of the protrusion is located at a position higher than the lower surface of each of the light source elements.

[0008] According to a second disclosed aspect, a lighting unit includes: the above-described light source unit; and an illumination optical system that guides light emitted from the light source unit to an illuminated object.

[0009] According to the third disclosed aspect, the lighting unit comprises: a plurality of the above-mentioned light source units; and an illumination optical system including a synthesis optical element for synthesizing light emitted from the plurality of the light source units, and guiding the synthesized light emitted from the synthesis optical element to an illuminated object.

[0010] According to a fourth disclosed aspect, an exposure apparatus includes: the lighting unit described above; and a projection optical system that projects a pattern image of a photomask illuminated by the lighting unit onto a photosensitive substrate.

[0011] According to a fifth disclosed aspect, an exposure method is an exposure method using the above-mentioned exposure device, comprising: illuminating a photomask using the lighting unit; and projecting a pattern image of the photomask onto a photosensitive substrate using the projection optical system.

[0012] It should be noted that the configuration of the embodiments described below may be appropriately improved, and at least a portion may be replaced by other components. Moreover, the technical features that are not particularly limited in their configuration are not limited to the configuration disclosed in the embodiments, and can be configured at a position that can achieve their functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram showing the structure of an exposure apparatus according to an embodiment.

[0014] Figure 2 This is a schematic diagram showing the structure of the lighting unit.

[0015] Figure 3 (A) is a plan view schematically showing the configuration of the first light source array and the second light source array. Figure 3 (B) is a diagram schematically showing the internal structure of the first light source unit and the second light source unit.

[0016] Figure 4 (A) is a top view of a substrate showing an embodiment, Figure 4 (B) is Figure 4 (A) AA line cross-sectional view.

[0017] Figure 5 (A)~ Figure 5 (H) is a diagram showing a method for manufacturing the first light source array.

[0018] Figure 6 (A) is a top view showing an example of a protruding portion of Modification Example 1, Figure 6 (B) is Figure 6 (A) AA line cross-sectional view.

[0019] Figure 7 (A) is a top view showing an example of a protrusion of Modification Example 2, Figure 7 (B) is Figure 7 (A) AA line cross-sectional view.

[0020] Figure 8 (A) is a top view showing an example of a protrusion of Modification Example 3, Figure 8 (B) is Figure 8 (A) AA line cross-sectional view. DETAILED DESCRIPTION

[0021] based on Figure 1 to Figure 5 (H) An exposure device 10 according to an embodiment is described.

[0022] (Configuration of Exposure Apparatus)

[0023] First, use Figure 1The configuration of exposure apparatus 10 according to one embodiment will be described. Figure 1 This is a diagram schematically showing the configuration of an exposure device 10 according to one embodiment.

[0024] The exposure device 10 is a scanning stepper (scanner) that drives the mask MSK and the glass substrate (hereinafter referred to as "substrate") P in the same direction and at the same speed relative to the projection optical system PL, thereby transferring the pattern formed on the mask MSK to the substrate P. The substrate P is, for example, a rectangular glass substrate used in a liquid crystal display device (flat panel display), and the length of at least one side or the diagonal length is 500 mm or more.

[0025] Below, the direction (scanning direction) in which the mask MSK and the substrate P are driven during scanning exposure is set as the X-axis direction, the direction in the horizontal plane orthogonal to it is set as the Y-axis direction, the direction orthogonal to the X-axis and the Y-axis is set as the Z-axis direction, and the rotation (tilt) directions around the X-axis, Y-axis, and Z-axis are set as θx, θy, and θz directions, respectively.

[0026] The exposure device 10 includes an illumination system IOP, a mask stage MST holding a mask MSK, a projection optical system PL, a main body 70 supporting these parts, a substrate stage PST holding a substrate P, and control systems for these parts. The control system collectively controls the components of the exposure device 10.

[0027] The main body 70 includes a base (vibration-proof table) 71, columns 72A and 72B, an optical fixing plate 73, a support body 74, and a sliding guide 75. The base (vibration-proof table) 71 is arranged on the ground F, and supports the columns 72A and 72B and the like while isolating vibration from the ground F. The columns 72A and 72B each have a frame shape, and the column 72A is arranged inside the column 72B. The optical fixing plate 73 has a flat plate shape and is fixed to the top of the column 72A. The support body 74 is supported on the top of the column 72B via the sliding guide 75. The sliding guide 75 has a balloon lifter and a positioning mechanism, and positions the support body 74 (i.e., the mask stage MST described later) at an appropriate position in the X-axis direction relative to the optical fixing plate 73.

[0028] The illumination system IOP is arranged above the main 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.

[0029] The mask stage MST is supported by a support body 74. It has a pattern surface ( Figure 1The mask MSK (the lower surface of the optical system) is fixed to the mask stage MST by, for example, vacuum adsorption (or electrostatic adsorption). The mask stage MST is driven by a drive system including, for example, a linear motor with a predetermined stroke in the scanning direction (X-axis direction) and is slightly driven in the non-scanning direction (Y-axis direction and θz direction).

[0030] The position information of the mask stage MST in the XY plane (including the rotation information in the θz direction) is measured by the interferometer system. The interferometer system irradiates the moving mirror (or the reflective surface (not shown) obtained by mirror processing) provided at the end of the mask stage MST with a length measurement beam, receives the reflected light from the moving mirror, and thereby measures the position of the mask stage MST. The measurement result is supplied to the control device (not shown), and the control device drives the mask stage MST with the help of the drive system according to the measurement result of the interferometer system.

[0031] The projection optical system PL is supported on the optical fixing plate 73 below the mask stage MST (-Z side). The projection optical system PL is configured similarly to the projection optical system disclosed in, for example, the specification of U.S. Patent No. 5,729,331, and includes a projection area of ​​the pattern image of the mask MSK, for example, a plurality of (for example, 7) projection optical units 100 (multi-lens projection optical units) arranged in a staggered manner, forming an image field in a rectangular shape with the Y-axis direction as the long side direction. Here, four projection optical units 100 are arranged at a predetermined interval in the Y-axis direction, and the remaining three projection optical units 100 are separated from the four projection optical units 100 to the +X side and arranged at a predetermined interval in the Y-axis direction. As each of the plurality of projection optical units 100, a unit that forms an erect image using, for example, a double telecentric equal magnification system is used. It should be noted that the plurality of projection areas of the projection optical units 100 arranged in a staggered manner are collectively referred to as exposure areas.

[0032] When the illumination area on the mask MSK is illuminated by the illumination light IL from the illumination system IOP, the illumination light IL that has passed through the mask MSK is used to form a projection image (partial erect image) of the circuit pattern of the mask MSK in the illumination area on the irradiated area (exposure area (conjugate with the illumination area)) on the substrate P arranged on the image plane side of the projection optical system PL with the aid of the projection optical system PL. Here, a resist (sensitizer) is applied on the surface of the substrate P. The mask stage MST and the substrate stage PST are driven synchronously, that is, the mask MSK is driven in the scanning direction (X-axis direction) relative to the illumination area (illumination light IL), and the substrate P is driven in the same scanning direction relative to the exposure area (illumination light IL), thereby exposing the substrate P and transferring the pattern of the mask MSK onto the substrate P.

[0033] The substrate stage PST is disposed on a base (anti-vibration table) 71 below (at the −Z side) the projection optical system PL. The substrate P is held on the substrate stage PST via a substrate holder (not shown).

[0034] The position information of the substrate stage PST in the XY plane (including rotation information (deflection amount (rotation amount θz in the θz direction), pitch amount (rotation amount θx in the θx direction), roll amount (rotation amount θy in the θy direction))) is measured by the interferometer system. The interferometer system irradiates a length measurement beam from the optical fixing plate 73 to a movable mirror (or a reflective surface obtained by mirror processing (not shown)) provided at the end of the substrate stage PST, receives reflected light from the movable mirror, and thereby measures the position of the substrate stage PST. The measurement results are supplied to a control device (not shown), and the control device drives the substrate stage PST according to the measurement results of the interferometer system.

[0035] In the exposure device 10, alignment measurement (for example, EGA, etc.) is performed before exposure, and the result is used to expose the substrate P according to the following steps. First, according to the instructions of the control device, the mask stage MST and the substrate stage PST are synchronously driven along the X-axis direction. Thus, scanning exposure to the first shooting area on the substrate P is performed. If the scanning exposure relative to the first shooting area is completed, the control device moves the substrate stage PST to a position corresponding to the second shooting area (stepping). Then, scanning exposure relative to the second shooting area is performed. The control device repeats the stepping between the shooting areas of the substrate P and the scanning exposure relative to the shooting areas in the same way, and transfers the pattern of the mask MSK to all the shooting areas on the substrate P.

[0036] (Composition of the lighting system IOP)

[0037] Next, the configuration of the illumination system IOP in the present embodiment will be described. The illumination system IOP includes a plurality of illumination units 90 corresponding to the plurality of projection optical units 100 included in the projection optical system PL. Figure 2 It is a diagram schematically showing the structure of the lighting unit 90.

[0038] The illumination unit 90 includes a first light source unit OPU1 , a second light source unit OPU2 , and an illumination optical system 80 .

[0039] (Configuration of light source unit)

[0040] The first light source unit OPU1 includes a first light source array 20A and a first magnifying optical system 30A, and the second light source unit OPU2 includes a second light source array 20B and a second magnifying optical system 30B.

[0041] Figure 3(A) is a plan view schematically showing the configuration of the first light source array 20A and the second light source array 20B. Figure 3 (B) is a diagram schematically showing the internal structure of the first light source unit OPU1 and the second light source unit OPU2.

[0042] like Figure 3 As shown in (A), the first light source array 20A has a plurality of light sources (in Figure 3 In (A), there are 5×5 LED (Light Emitting Diode) chips 23A. The number of LED chips 23A can be changed as needed. The LED chips 23A are arranged at a pitch P1, which is the distance between the centers of adjacent LED chips 23A.

[0043] Each of the plurality of LED chips 23A has a light emitting portion 231A, and the peak wavelength of the light emitted from the light emitting portion 231A is within the range of 380 to 390 nm. That is, the light emitting portion 231A is an ultraviolet LED (UV LED). The peak wavelength of the light emitted from the light emitting portion 231A is more preferably 385 nm. The light emitting surface of the light emitting portion 231A is a square, and the length of one side thereof is a1. It should be noted that in the following description, the two directions in which the LED chips 23A are arranged are set as the X1 direction and the Y1 direction. The X1 direction and the Y1 direction are orthogonal. In addition, the direction orthogonal to the X1 direction and the Y1 direction is set as the Z1 direction. The Z1 direction is approximately parallel to the optical axis OA of the light emitted from the light emitting portion 231A.

[0044] The first magnifying optical system 30A is a magnifying optical system for forming magnified images of the light emitting portions 231A of the respective LED chips 23A on the predetermined plane PP. Figure 3 As shown in (B), the first magnifying optical system 30A includes a plurality of lens portions 31A arranged in a manner corresponding to the arrangement of the LED chips 23A. The lens portions 31A are a double telecentric optical system that magnifies and projects the light emitting portion 231A at a magnification M1 greater than (the arrangement pitch P1 of the LED chips 23A) / (the length a1 of one side of the light emitting surface of the light emitting portion 231A). It should be noted that in Figure 3 In (B), only four LED chips 23A (23B) arranged in a row along the Y1 direction are shown for clarity of the drawing.

[0045] The second light source array 20B includes, for example, a plurality of light sources (in Figure 3The number of LED chips 23B can be changed as needed. The LED chips 23B are arranged at a pitch P2, where the pitch P2 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 can be the same or different.

[0046] Each of the plurality of LED chips 23B has a light emitting portion 231B, and the peak wavelength of the light emitted from the light emitting portion 231B is within the range of 360 to 370 nm. That is, the light emitting portion 231B is a UV LED. The peak wavelength of the light emitted from the light emitting portion 231B is more preferably 365 nm. The light emitting surface of the light emitting portion 231B is a square, and the length of one side thereof is a2.

[0047] The second magnifying optical system 30B is a magnifying optical system for forming magnified images of the light emitting portions 231B of the respective LED chips 23B on the predetermined plane PP. Figure 3 As shown in (B), there are a plurality of lens portions 31B arranged in a manner corresponding to the arrangement of the LED chips 23B. The lens portion 31B is a double telecentric optical system that enlarges and projects the light emitting portion 231B by a magnification M2 greater than (the arrangement pitch P2 of the LED chips 23B) / (the length a2 of one side of the light emitting surface of the light emitting portion 231B).

[0048] In this embodiment, the lens portions 31A and 31B each have four plano-convex lenses, but the present invention is not limited thereto, and the lens portions 31A and 31B may have, for example, two biconvex lenses or three biconvex lenses. In addition, the lens portions 31A and 31B may also have, for example, plano-convex lenses and biconvex lenses.

[0049] Here, in the manufacturing process of the first light source array 20A and the second light source array 20B, when the LED chips 23A and 23B are arranged and fixed on the substrates 21A and 21B (more specifically, when the solder paste is reflowed), the fixed positions of the LED chips 23A and 23B are sometimes misaligned with the designed positions. The misalignment of the LED chips 23A and 23B causes the illumination of the light emitted from the first light source unit OPU1 and the second light source unit OPU2 to decrease.

[0050] Therefore, the substrates 21A and 21B of the present embodiment are provided with protrusions 211 for suppressing positional displacement of the LED chips 23A and 23B during manufacturing, and the protrusions 211 are constituted by a part of the substrates 21A and 21B. Figure 4 (A) and Figure 4 (B) is a diagram for explaining the protrusion 211 provided on the substrates 21A and 21B. Figure 4 (A) is a top view of the substrates 21A and 21B. Figure 4 (B) is Figure 4 AA line cross-sectional view of (A). It should be noted that the structure of the protrusion 211 provided on the substrates 21A and 21B is the same, so the substrate 21A will be described here. Figure 4 (A) and Figure 4 In (B), for the sake of convenience, a portion of the LED chip 23A is shown. Figure 4 In (B), the hatching of the LED chip 23A is omitted.

[0051] The protrusion 211 is provided between the plurality of LED chips 23A. Figure 4 (A) and Figure 4 As shown in (B), the cross-shaped protrusion 211 is provided adjacent to the corner of each LED chip 23A. Figure 4 As shown in (B), the end 211a of the protrusion 211 is located at a position higher than the lower surface of the LED chip 23A (the surface on the -Z1 side). The height of the protrusion 211 only needs to be a height at which the end 211a is located higher than the lower surface of the LED chip 23A and does not block the light emitted from the LED chip 23A. In addition, the shape of the protrusion 211 only needs to be a shape in which the light emitted from the LED chip 23A does not enter the protrusion 211. The protrusion 211 and the LED chip 23A may be in contact, or there may be a gap between the protrusion 211 and the LED chip 23A.

[0052] When manufacturing the first light source array 20A, the LED chip 23A is arranged in the area defined by the four adjacent protrusions 211 (the area surrounded by the four protrusions 211). The end 211a of the protrusion 211 is located at a position higher than the lower surface of the LED chip 23A, so the movement of the LED chip 23A arranged in this area is restricted. Therefore, when the LED chip 23A is fixed to the substrate 21A, the displacement of the LED chip 23A is suppressed. As a result, the LED suppresses the decrease in illumination caused by the displacement of the chip 23A, and the first light source unit OPU1 can emit high-brightness light.

[0053] (Configuration of Illumination Optical System 80)

[0054] return Figure 2 The illumination optical system 80 includes a first light collecting optical system (first optical system) 81A including a first dichroic mirror DM1, a second light collecting optical system (second optical system) 81B, a second dichroic mirror DM2, an imaging optical system 83, a fly-eye lens FEL, and a capacitance optical system 84.

[0055] The first light-collecting optical system 81A forms a pupil of the magnified image of the light-emitting portion 231A formed by the first magnifying optical system 30A. That is, the rear focal position of the first light-collecting optical system 81A becomes the position of the pupil. The first light-collecting optical system 81A has a first dichroic mirror DM1 in the middle of the optical path, which reflects at least a portion of the light with a peak wavelength of 385 nm. Thus, the light beam is incident on the second dichroic mirror DM2. It should be noted that the first light-collecting optical system 81A can be a structure without the first dichroic mirror DM1. In this case, it is sufficient to appropriately adjust the configuration of the first light source unit OPU1 and the configuration of each lens of the first light-collecting optical system 81A so that the light beam is incident on the second dichroic mirror DM2. In addition, the first light-collecting optical system 81A can be composed of one lens, or a lens group including a plurality of lenses.

[0056] The second light collecting optical system 81B forms a pupil of the magnified image of the light emitting unit 231B formed by the second enlarging optical system 30B. That is, the rear focus position of the second light collecting optical system 81B becomes the position of the pupil. The second light collecting optical system 81B may be formed by a single lens or a lens group including a plurality of lenses.

[0057] 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 in which the pupil image formed by the first light collecting optical system 81A and the pupil image formed by the second light collecting optical system 81B overlap.

[0058] In the present embodiment, the second dichroic mirror DM2 makes the pupil image formed by the first light-collecting optical system 81A overlap with the pupil image formed by the second light-collecting optical system 81B to form a composite image. That is, the second dichroic mirror DM2 is arranged at the following position, that is, arranged at the rear focal position of the first light-collecting optical system 81A and arranged at the rear focal position of the second light-collecting optical system 81B. Thus, the second dichroic mirror DM2 performs Kohler illumination on the light emitted from the first light source unit OPU1 and the light emitted from the second light source unit OPU2. By performing Kohler illumination, the illumination change of the light beam of the pupil image formed by the first light-collecting optical system 81A and the illumination change of the light beam of the pupil image formed by the second light-collecting optical system 81B can be reduced. It should be noted that, without being limited to the configuration of the present embodiment, the first light-collecting optical system 81A and the second light-collecting optical system 81B can also be configured to perform critical illumination to form the image of the first light source unit OPU1 and the image of the second light source unit OPU2 in the second dichroic mirror DM2, respectively.

[0059] The lighting unit 90 is provided with a detector DT10 for monitoring light having a peak wavelength of 385 nm, a detector DT20 for monitoring light having a peak wavelength of 365 nm, and a detector DT30 for monitoring light having a peak wavelength of 385 nm and light having a peak wavelength of 365 nm.

[0060] Specifically, the detector DT10 detects the illuminance of the light with a peak wavelength of 385 nm reflected by the first dichroic mirror DM1. The detector DT20 detects the illuminance of the light with a peak wavelength of 365 nm reflected by the second dichroic mirror DM2. The detector DT30 detects the illuminance of the light with a peak wavelength of 385 nm unintentionally reflected by the second dichroic mirror DM2 and the illuminance of the light with a peak wavelength of 365 nm unintentionally transmitted by the second dichroic mirror DM2.

[0061] The detection results of the detectors DT10 to DT30 are output to a control device (not shown), and the control device controls the value of the current supplied to the LED chips 23A and 23B respectively possessed by the first light source unit OPU1 and the second light source unit OPU2 based on the detection results of the detectors DT10 to DT30.

[0062] The imaging optical system 83 is a double telecentric optical system that projects the composite image synthesized by the second dichroic mirror DM2 to the incident end of the fly-eye lens FEL at the same magnification. It should be noted that the imaging optical system 83 can also reduce the composite image synthesized by the second dichroic mirror DM2 and project it to the incident end of the fly-eye lens FEL.

[0063] The fly-eye lens FEL is constructed by, for example, arranging a plurality of lens elements having positive refractive power in a dense manner in a vertical and horizontal manner 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 (the shape of the exposure area to be finally formed on the plate P).

[0064] Therefore, the light beam incident on the fly-eye lens FEL is divided by the wavefronts of multiple lens elements, and a light source image is formed on the rear focal plane (exit plane) of each lens element or in the vicinity thereof. That is, a substantial surface light source composed of multiple light source images, that is, a secondary light source, is formed on the rear focal plane (exit plane) of the fly-eye lens FEL or in the vicinity thereof. The light beam from the secondary light source formed on the rear focal plane (exit plane) of the fly-eye lens FEL or in the vicinity thereof is incident on the opening aperture 85 arranged in the vicinity thereof. It should be noted that in the present embodiment, the rear focal plane (exit plane) of the fly-eye lens FEL, the first light source array 20A, and the second light source array 20B are optically conjugate.

[0065] The aperture stop 85 is arranged at a position that is almost optically conjugate with the incident pupil plane of the projection optical system PL, and has a variable aperture portion for defining a range that contributes to the illumination of the secondary light source. Then, the aperture stop 85 sets the σ value (the ratio of the aperture of the secondary light source image on the pupil plane of the projection optical system to the aperture of the pupil plane) that determines the illumination condition to a desired value by changing the aperture of the variable aperture portion. The light from the secondary light source that has passed through the aperture stop 85, after receiving the light collecting action of the capacitor optical system 84, overlaps and illuminates the mask MSK formed with a prescribed pattern.

[0066] It should be noted that the wavelengths of the light emitted by the first light source unit OPU1 and the second light source unit OPU2 are not limited to the above-mentioned wavelengths, and the first light source unit OPU1 and the second light source unit OPU2 may be appropriately combined with LED chips that emit light having a peak wavelength in the range of 360 to 440 nm. For example, it may be configured so that the first light source unit OPU1 emits light having a peak wavelength of 405 nm, and the second light source unit OPU2 emits light having a peak wavelength of 385 nm. In addition, it may be configured so that the first light source unit OPU1 emits light having a peak wavelength of 395 nm, and the second light source unit OPU2 emits light having a peak wavelength of 385 nm. The combination of the wavelength of the light emitted from the first light source unit OPU1 and the wavelength of the light emitted from the second light source unit OPU2 is not limited to these examples. It should be noted that when the combination of the wavelength of the light emitted from the first light source unit OPU1 and the wavelength of the light emitted from the second light source unit OPU2 is set to a combination other than the first embodiment, it is preferred to appropriately change the material of the dichroic mirror according to the wavelength used.

[0067] (Method for manufacturing light source array)

[0068] Next, a method for manufacturing the first light source array 20A and the second light source array 20B will be described. The method for manufacturing the first light source array 20A and the second light source array 20B is the same, so the first light source array 20A will be described here.

[0069] Figure 5 (A)~ Figure 5 (H) is a diagram showing a method for manufacturing the first light source array 20A. Figure 5 (B) is Figure 5 (A) AA line cross-sectional view, Figure 5 (D) is Figure 5 (C) BB line cross-sectional view, Figure 5 (F) is Figure 5 (E) CC line cross-sectional view, Figure 5 (H) is Figure 5 DD line cross-sectional view of (G).

[0070] First, if Figure 5 (A) and Figure 5 As shown in (B), a substrate 21A is prepared. The substrate 21A is a substrate made of metal such as copper (Cu).

[0071] like Figure 5 (C) and Figure 5 As shown in (D), the substrate 21A is etched to form the pillars 212 and the protrusions 211. Thus, the protrusions 211 are formed by a part of the substrate 21A, so that the strength of the protrusions 211 is improved. Etching is performed, for example, using a resist patterned by a photolithography process as a mask.

[0072] Next, if Figure 5 (E) and Figure 5 As shown in (F) of FIG. 1 , an insulating layer 221 and a wiring layer 222 are sequentially formed on the substrate 21A. Figure 5 (G) and Figure 5 As shown in (H), solder paste 223 is applied on the upper surface of the pillar 212 and the wiring layer 222, and the LED chip 23A is arranged in the area defined by the protrusion 211. Thereafter, the LED chip 23A is fixed to the substrate 21A by reflow soldering. At this time, since the movement of the LED chip 23A is restricted by the protrusion 211, the misalignment of the LED chip 23A is suppressed. Through the above processing, the first light source array 20A in which the misalignment of the LED chip 23A is suppressed can be obtained. It should be noted that, as shown in the figure, in the present embodiment, each LED chip 23A is connected in series in the X1 direction.

[0073] As described above in detail, according to the present embodiment, the first light source unit OPU1 has a plurality of LED chips 23A arranged two-dimensionally on the surface of the substrate 21A, and a protrusion 211 protruding from the substrate 21A and provided between the plurality of LED chips 23A. The end 211a of the protrusion 211 is located at a position higher than the lower surface of the LED chip 23A. Thus, when the LED chip 23A is fixed to the substrate 21A, the protrusion 211 restricts the movement of the LED chip 23A to suppress the misalignment of the LED chip 23A, thereby suppressing the reduction in the illumination of the first light source unit OPU1. Therefore, the first light source unit OPU1 can realize a high-brightness surface light source.

[0074] According to the present embodiment, the substrate 21A is formed of a metal material, so that the protrusion 211 can be easily formed by etching or the like.

[0075] According to the present embodiment, the protrusion 211 is formed by a part of the substrate 21A. Thus, the protrusion 211 has high strength.

[0076] (Variant 1)

[0077] In the above embodiment, the protrusion 211 is provided adjacent to the corner of the LED chip 23A, but the present invention is not limited thereto and the protrusion 211 may be provided between each LED chip 23A and at least one of the other LED chips 23A adjacent to the LED chip 23A.

[0078] Figure 6 (A) is a plan view showing an example of the protrusion 211A of the modification example 1, Figure 6 (B) is Figure 6 The AA line section view of (A). Figure 6 (A) and Figure 6 As shown in (B), the protrusion 211A of modification example 1 is cylindrical. In modification example 1, when the LED chips 23A arranged in 2 rows × 2 rows in the X1 direction and the Y1 direction are set as 1 group (indicated by double-dashed lines), the protrusion 211A is provided between the LED chips 23A adjacent to each other in the X1 direction and between the LED chips 23A adjacent to each other in the Y1 direction within 1 group. In addition, the protrusion 211A is not provided between the adjacent groups in the X1 direction and the Y1 direction, but the protrusion 211A may be provided between adjacent groups. The protrusion 211A and the LED chip 23A may be in contact, or there may be a gap between the protrusion 211A and the LED chip 23A.

[0079] When the substrate 21A has such a protrusion 211A, when manufacturing the first light source array 20A, the LED chip 23A is pressed against the protrusion 211A by a jig or the like and reflow soldering is performed, thereby suppressing the displacement of the LED chip 23A. It should be noted that a mechanism for pressing the LED chip 23A against the protrusion 211A may also be provided on the substrate 21A.

[0080] When the cylindrical protrusion 211A of Modification 1 is used, the LED chip 23A is in point contact with the protrusion 211A, so the positioning accuracy of the LED chip 23A is improved.

[0081] For example, within one group, a cross-shaped protrusion 211 may be disposed in the center, and cylindrical protrusions 211A may be disposed between LED chips 23A adjacent in the X1 direction and between LED chips 23A adjacent in the Y1 direction.

[0082] (Variant 2)

[0083] Figure 7 (A) is a plan view showing an example of the protrusion 211B of the modification example 2, Figure 7 (B) is Figure 7 The AA line section view of (A). Figure 7 (A) and Figure 7 As shown in (B), in Modification 2, in 1 group indicated by double-dashed lines, a wall-shaped protrusion 211B is provided between LED chips 23A adjacent to each other in the X1 direction and between LED chips 23A adjacent to each other in the Y1 direction. In this case, as in Modification 1, by pressing the LED chip 23A against the protrusion 211B for reflow soldering, it is possible to suppress the misalignment of the LED chip 23A. The protrusion 211B and the LED chip 23A may be in contact, or there may be a gap between the protrusion 211B and the LED chip 23A. In addition, in this Modification 2, the protrusion 211B is not provided between the adjacent groups in the X1 direction and the Y1 direction, but the protrusion 211B may be provided between adjacent groups.

[0084] It should be noted that the wall-shaped protrusion 211B may be provided adjacent to each side of the LED chip 23A. In this case, by arranging the LED chip 23A in the region surrounded by the wall-shaped protrusion 211B, it is possible to suppress displacement of the LED chip 23A.

[0085] (Variant 3)

[0086] In the above-described embodiment and Modifications 1 and 2, the protrusions 211 , 211A, and 211B are adjacent to, for example, a portion of the side of the LED chip 23A. However, the protrusion 211 may be formed to protect the entire circumference of the LED chip 23A. Figure 8 (A) is a plan view showing an example of a protrusion 211C of Modification 3, Figure 8 (B) is Figure 8 AA line cross-sectional view of (A). In modification 3, by forming a recess 213 for accommodating the LED chip 23A in the substrate 21A, the protrusion 211C is obtained. Thus, the protrusion 211C surrounds the entire circumference of the LED chip 23A. By accommodating the LED chip 23A in the recess 213, the displacement of the LED chip 23A can be suppressed.

[0087] It should be noted that, in the above-mentioned embodiment and modified examples 1 to 3, the case where the protrusions 211, 211A, 211B, and 211C are composed of a part of the substrate 21A is described, but the present invention is not limited to this. For example, in the embodiment and modified examples 1 and 2, the protrusions 211, 211A, and 211B may be a member different from the substrate 21A (a member separate from the substrate 21A) that contacts the substrate 21A. That is, the protrusions 211, 211A, and 211B may be formed by fixing (welding, bonding) a member different from the substrate 21A to the substrate 21A. In this case, the protrusions 211, 211A, and 211B may be formed of the same material as the substrate 21A, or may be formed of a different material.

[0088] In addition, in the above-mentioned embodiment and modified examples 1 to 3, the LED chip 23A is arranged on the substrate 21A, but it is not limited to this. The LED chip 23A can also be arranged on a heat sink. The same is true for the LED chip 23B. As a heat sink, for example, a microchannel heat sink having a flow path for circulating a coolant inside and a fin-type heat sink are cited. If the temperature of the LED chip 23A rises, the light amount of the LED decreases, but by arranging the LED chip 23A on the heat sink, the temperature rise of the LED chip 23A can be suppressed.

[0089] In the above-mentioned embodiment and modified examples 1 to 3, the lighting unit 90 includes the lighting optical system 80 including the first light source unit OPU1, the second light source unit OPU2, and the second dichroic mirror DM2, but is not limited thereto. For example, the lighting unit 90 may include only one of the first light source unit OPU1 and the second light source unit OPU2. In this case, the lighting optical system 80 may have any configuration as long as it can guide the light emitted from the first light source unit OPU1 or the second light source unit OPU2 to the light mask MSK.

[0090] The above-mentioned embodiments are preferred examples of the present invention, but are not limited thereto, and various modifications can be made without departing from the gist of the present invention.

[0091] Description of Reference Numerals

[0092] 10Exposure device

[0093] 20A 1st light source array

[0094] 20B Second light source array

[0095] 21A, 21B substrate

[0096] 23A, 23B LED chips

[0097] 31A, 31B lens part

[0098] 80 Illumination optical system

[0099] 90 Lighting units

[0100] 100 Projection optical unit

[0101] 211, 211A, 211B, 211C protrusions

[0102] 211a end

[0103] 231A, 231B light emitting unit

[0104] DM2 Second dichroic mirror

[0105] MSK Photomask

[0106] OPU1 1st light source unit

[0107] OPU2 Second Light Source Unit

[0108] P substrate.

Claims

1. A light source unit, comprising: A plurality of light source elements arranged two-dimensionally on a surface of a fixed object; and a protrusion that protrudes from the fixing object and is provided between each of the plurality of light source elements and at least one of the other light source elements adjacent to each of the light source elements, An end portion of the protrusion is located higher than a lower surface of each of the light source elements.

2. The light source unit according to claim 1, wherein: The fixing object is a substrate or a heat sink.

3. The light source unit according to claim 2, wherein: The radiator has a flow path through which a coolant flows.

4. The light source unit according to any one of claims 1 to 3, wherein: The fixing object is formed of a metal material.

5. The light source unit according to any one of claims 1 to 4, wherein: The protrusion is constituted by a part of the fixing object.

6. The light source unit according to any one of claims 1 to 4, wherein: The protrusion is formed of a member that contacts the fixing object and is different from the fixing object.

7. The light source unit according to any one of claims 1 to 6, wherein: Light emitted from the plurality of light source elements is not incident on the protruding portion.

8. The light source unit according to any one of claims 1 to 7, wherein: When the light source elements among the plurality of light source elements that are arranged in 2 rows × 2 rows in a first direction and in a second direction intersecting the first direction are taken as a group, the protrusion is provided within the group between the light source elements adjacent to each other in the first direction and between the light source elements adjacent to each other in the second direction.

9. The light source unit according to claim 8, wherein: In at least one of the first direction and the second direction, the protruding portion is not provided between adjacent groups of the light source elements.

10. The light source unit according to any one of claims 1 to 9, wherein: Each of the plurality of light source elements has a light emitting portion for emitting light. The light source unit further includes a lens array in which a plurality of lens portions are arranged on a two-dimensional plane, and the lens portion forms an enlarged image of the light emitting portion of each of the plurality of light source elements.

11. The light source unit according to any one of claims 1 to 10, wherein: The light source element is a light emitting diode element.

12. The light source unit according to any one of claims 1 to 11, wherein: The light source element emits light with a wavelength of 400 nm or less.

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

14. A lighting unit comprising: A plurality of light source units according to any one of claims 1 to 12; and The illumination optical system includes a synthesis optical element for synthesizing the light emitted from the plurality of light source units, and guides the synthesized light emitted from the synthesis optical element to an irradiated object.

15. An exposure device comprising: The lighting unit of claim 13 or 14; and The projection optical system projects the pattern image of the mask illuminated by the illumination unit onto the photosensitive substrate.

16. The exposure apparatus according to claim 15, wherein: The photosensitive substrate has at least one side or a diagonal length of 500 mm or more.

17. An exposure method using the exposure apparatus according to claim 15 or 16, the exposure method comprising: Utilizing the lighting unit to illuminate the light shield; as well as The pattern image of the mask is projected onto a photosensitive substrate using the projection optical system.

Images