JP2004012900A - Aligner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aligner capable of exposing a target without being influenced by dust or the like. <P>SOLUTION: The aligner is provided with a base board 174 for erecting the exposing surface of a held exposed material 148, an exposing head 166 which is moved relatively to the base board 174 to expose the exposing surface in accordance with image data and a scanning means for moving the exposing head 166 on the upright surface. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exposure apparatus including an exposure head that exposes an exposure material with a light beam modulated by a spatial light modulator in accordance with image data.
[0002]
[Prior art]
Conventionally, various exposure apparatuses that perform image exposure with a light beam modulated in accordance with image data using a spatial light modulation element such as a digital micromirror device (DMD) have been proposed. For example, the DMD is a mirror device in which a number of micromirrors whose reflection surfaces change in response to a control signal are two-dimensionally arranged on a semiconductor substrate such as silicon. An exposure apparatus using this DMD is As shown in FIG. 21A, the light source 1 that irradiates laser light, the lens system 2 that collimates the laser light emitted from the light source 1, and the DMD 3 and DMD 3 that are arranged at substantially the focal position of the lens system 2 are reflected. It comprises lens systems 4 and 6 that form an image of the laser beam on the scanning surface 5.
[0003]
In the above exposure apparatus, each of the micromirrors of the DMD 3 is controlled on and off by a control apparatus (not shown) according to a control signal generated according to image data or the like, and laser light is modulated, and image exposure is performed with the modulated laser light. ing. Conventionally, the exposure material is attracted and held on a base called a stage, and the exposure head is disposed above the exposure material, and the stage moves in the longitudinal direction (sub-scanning direction). The exposure material is configured to be exposed.
[0004]
[Problems to be solved by the invention]
However, when the exposure head is exposed from above the exposure material in this way, dust or the like drifting around the exposure material falls on the surface (exposure surface) of the exposure material due to gravity, or even on the stage. If, for example, the exposure head moves while being supported so as to be movable on a rail, dust generated from the exposure head falls on the surface (exposure surface) of the exposure material due to wear of the connection portion between the exposure head and the rail. An unexpected failure sometimes occurred. In the case of analog exposure, particularly proxy exposure or contact exposure, dust or the like from the mask may fall on the exposure material, thereby causing a failure. Furthermore, when only the exposure from the upper side is necessary, a process of reversing the front and back is added when it is necessary to expose both sides, so the exposure processing speed is inevitably slowed.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide an exposure apparatus that can reliably perform exposure without being affected by dust or the like and that can also improve the exposure speed.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an exposure apparatus according to claim 1 of the present invention comprises a base for erecting an exposure surface of an exposure material to be held, and a relative movement with respect to the base, in accordance with image data. An exposure head for exposing the exposure surface, and scanning means for moving the base or the exposure head on an upright surface.
[0007]
With such a configuration, since the exposure material is held in an upright state, even if dust or the like falls due to gravity, it does not adhere to the exposure surface. Therefore, no failure or the like is caused thereby. Further, since the moving direction has a rigidity corresponding to the size of the base and the exposure material, the base and the exposure material are not warped or distorted due to gravity.
[0008]
An exposure apparatus according to a second aspect is the exposure apparatus according to the first aspect, wherein the base is transparent, and the exposure head exposes an exposure material from the back side of the base. According to this, by making the base material of the exposure material transparent, exposure can be performed without being affected by dust scattered on the exposure surface side.
[0009]
Furthermore, an exposure apparatus according to a third aspect is characterized in that, in the exposure apparatus according to the second aspect, the exposure head is also provided on the front side of the base, and the exposure material is exposed from both the front and back sides. According to this, it becomes possible to simultaneously expose both sides of an exposure material having exposure surfaces formed on both sides, and the exposure speed can be improved.
[0010]
The exposure apparatus according to claim 4 is an exposure device that exposes the exposure surface in accordance with image data, and a transparent base that horizontally supports the exposure surface of the exposure material to be held, and a relative base that moves relative to the base. And a scanning means for moving the base or the exposure head on a horizontal plane, wherein the exposure head exposes an exposure material from the back side of the base.
[0011]
According to this, since the exposure head exposes from the back side of the base, even if dust or the like falls due to gravity and adheres to the exposure surface, it is possible to avoid the influence.
[0012]
An exposure apparatus according to claim 5 is characterized in that, in the exposure apparatus according to claim 4, the exposure head is also provided on the front side of the base to expose the exposure material from both the front and back sides. According to this, it becomes possible to simultaneously expose both sides of an exposure material having exposure surfaces formed on both sides, and the exposure speed can be improved.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail based on examples shown in the drawings. First, the configuration of a conventional exposure apparatus that exposes an exposure material from above will be briefly described. As shown in FIG. 7, the exposure apparatus includes a flat stage 152 that holds a sheet-like exposure material 150 by adsorbing to the surface. Two guides 158 extending along the stage moving direction are installed on the upper surface of the thick plate-shaped installation table 156 supported by the four legs 154. The stage 152 is disposed so that the longitudinal direction thereof faces the stage moving direction, and is supported by a guide 158 so as to be reciprocally movable. The exposure apparatus is provided with a drive device (not shown) for driving the stage 152 along the guide 158.
[0014]
A U-shaped gate 160 is provided at the center of the installation table 156 so as to straddle the movement path of the stage 152. Each end of the U-shaped gate 160 is fixed to both side surfaces of the installation table 156. A scanner 162 is provided on one side of the gate 160, and a plurality of (for example, two) detection sensors 164 for detecting the front and rear ends of the exposure material 150 are provided on the other side. The scanner 162 and the detection sensor 164 are respectively attached to the gate 160 and fixedly arranged above the moving path of the stage 152. The scanner 162 and the detection sensor 164 are connected to a controller (not shown) that controls them.
[0015]
As shown in FIGS. 8 and 9B, the scanner 162 includes a plurality of (for example, 14) exposure heads 166 arranged in a substantially matrix of m rows and n columns (for example, 3 rows and 5 columns). ing. In this example, four exposure heads 166 are arranged in the third row in relation to the width of the exposure material 150. In the case where individual exposure heads arranged in the m-th row and the n-th column are shown, the exposure head 166 is used. _mn Is written.
[0016]
An exposure area 168 by the exposure head 166 has a rectangular shape with a short side in the sub-scanning direction. Therefore, as the stage 152 moves, a strip-shaped exposed area 170 is formed in the exposure material 150 for each exposure head 166. In addition, when showing the exposure area by each exposure head arranged in the mth row and the nth column, the exposure area 168 is shown. _mn Is written.
[0017]
Further, as shown in FIGS. 9A and 9B, each of the exposure heads in each row arranged in a line so that the strip-shaped exposed regions 170 are arranged in the direction orthogonal to the sub-scanning direction without gaps. In the arrangement direction, they are shifted by a predetermined interval (natural number times the long side of the exposure area, twice in this embodiment). Therefore, the exposure area 168 in the first row ₁₁ And exposure area 168 ₁₂ The portion that cannot be exposed between the exposure area 168 and the exposure area 168 in the second row ₂₁ And exposure area 168 in the third row ₃₁ And can be exposed.
[0018]
Exposure head 166 ₁₁ ~ 166 _mn As shown in FIGS. 10, 11 (A) and 11 (B), each is a digital micromirror device as a spatial light modulation element that modulates an incident light beam for each pixel in accordance with image data. (DMD) 50 is provided. The DMD 50 is connected to a controller (not shown) including a data processing unit and a mirror drive control unit. The data processing unit of this controller generates a control signal for driving and controlling each micromirror in the region to be controlled by the DMD 50 for each exposure head 166 based on the input image data. The area to be controlled will be described later.
[0019]
In addition, the mirror drive control unit controls the angle of the reflection surface of each micromirror of the DMD 50 for each exposure head 166 based on the control signal generated by the image data processing unit. The control of the angle of the reflecting surface will be described later. On the light incident side of the DMD 50, a fiber array light source 66 including a laser emitting section in which emission ends (light emitting points) of an optical fiber are arranged in a line along a direction corresponding to the long side direction of the exposure area 168, a fiber A lens system 67 for correcting the laser light emitted from the array light source 66 and condensing it on the DMD, and a mirror 69 for reflecting the laser light transmitted through the lens system 67 toward the DMD 50 are arranged in this order.
[0020]
The lens system 67 includes a pair of combination lenses 71 that collimate the laser light emitted from the fiber array light source 66 and a pair of combination lenses that correct the light quantity distribution of the collimated laser light to be uniform. 73 and a condensing lens 75 that condenses the laser light whose light quantity distribution is corrected on the DMD. With respect to the arrangement direction of the laser emitting ends, the combination lens 73 spreads the light beam at a portion close to the optical axis of the lens, and contracts the light beam at a portion away from the optical axis, and also in a direction perpendicular to the arrangement direction. In this case, the laser beam is corrected so that the light quantity distribution is uniform.
[0021]
Further, on the light reflection side of the DMD 50, lens systems 54 and 58 for forming an image of the laser light reflected by the DMD 50 on the scanning surface (exposed surface) 56 of the exposure material 150 are arranged. The lens systems 54 and 58 are arranged so that the DMD 50 and the exposed surface 56 are in a conjugate relationship.
[0022]
As shown in FIG. 12, the DMD 50 is configured such that a micromirror (micromirror) 62 is supported by a support on an SRAM cell (memory cell) 60, and a large number of (pixels) (pixels) are formed. For example, the mirror device is configured by arranging 600 × 800 micromirrors in a lattice pattern. Each pixel is provided with a micromirror 62 supported by a support column at the top, and a material having a high reflectance such as aluminum is deposited on the surface of the micromirror 62. The reflectance of the micromirror 62 is 90% or more. A silicon gate CMOS SRAM cell 60 manufactured on a normal semiconductor memory manufacturing line is disposed directly below the micromirror 62 via a support including a hinge and a yoke, and is entirely monolithic (integrated type). ).
[0023]
When a digital signal is written in the SRAM cell 60 of the DMD 50, the micromirror 62 supported by the support is inclined within a range of ± α degrees (for example, ± 10 degrees) with respect to the substrate side on which the DMD 50 is disposed with the diagonal line as the center. It is done. FIG. 13A shows a state in which the micromirror 62 is tilted to + α degrees in the on state, and FIG. 13B shows a state in which the micromirror 62 is tilted to −α degrees in the off state. Therefore, by controlling the inclination of the micromirror 62 in each pixel of the DMD 50 as shown in FIG. 12 according to the image signal, the light incident on the DMD 50 is reflected in the inclination direction of each micromirror 62. .
[0024]
FIG. 12 shows an example of a state in which a part of the DMD 50 is enlarged and the micromirror 62 is controlled to + α degrees or −α degrees. On / off control of each micromirror 62 is performed by a controller (not shown) connected to the DMD 50. A light absorber (not shown) is arranged in the direction in which the light beam is reflected by the micromirror 62 in the off state.
[0025]
Further, it is preferable that the DMD 50 is disposed with a slight inclination so that the short side forms a predetermined angle θ (for example, 1 ° to 5 °) with the sub-scanning direction. 14A shows the scanning trajectory of the reflected light image (exposure beam) 53 by each micromirror when the DMD 50 is not tilted, and FIG. 14B shows the scanning trajectory of the exposure beam 53 when the DMD 50 is tilted. Show.
[0026]
In the DMD 50, a number of micromirror arrays in which a large number (for example, 800) of micromirrors are arranged in the longitudinal direction are arranged in a short direction (for example, 600 sets). As shown, the pitch P of the scanning trajectory (scanning line) of the exposure beam 53 by each micromirror is obtained by inclining the DMD 50. ₁ However, the pitch P of the scanning line when the DMD 50 is not inclined. ₂ It becomes narrower and the resolution can be greatly improved. On the other hand, since the tilt angle of the DMD 50 is very small, the scanning width W when the DMD 50 is tilted. ₂ And the scanning width W when the DMD 50 is not inclined. ₁ Is substantially the same.
[0027]
Further, the same scanning line is overlapped and exposed (multiple exposure) by different micromirror rows. In this way, by performing multiple exposure, it is possible to control a minute amount of the exposure position and to realize high-definition exposure. Further, the joints between a plurality of exposure heads arranged in the main scanning direction can be connected without a step by a very small exposure position control. Note that the same effect can be obtained by arranging the micromirror rows in a staggered manner by shifting the micromirror rows by a predetermined interval in a direction orthogonal to the sub-scanning direction instead of tilting the DMD 50.
[0028]
As shown in FIG. 15A, the fiber array light source 66 includes a plurality of (for example, six) laser modules 64, and one end of the multimode optical fiber 30 is coupled to each laser module 64. Yes. The other end of the multimode optical fiber 30 is coupled with an optical fiber 31 having the same core diameter as the multimode optical fiber 30 and a cladding diameter smaller than the multimode optical fiber 30, as shown in FIG. A laser emission portion 68 is configured by arranging the emission end portions (light emission points) of the optical fiber 31 in one row along the main scanning direction orthogonal to the sub-scanning direction. As shown in FIG. 15D, the light emitting points can be arranged in two rows along the main scanning direction.
[0029]
As shown in FIG. 15B, the emission end of the optical fiber 31 is sandwiched and fixed between two support plates 65 having a flat surface. Further, a transparent protective plate 63 such as glass is disposed on the light emitting side of the optical fiber 31 in order to protect the end face of the optical fiber 31. The protection plate 63 may be disposed in close contact with the end surface of the optical fiber 31 or may be disposed so that the end surface of the optical fiber 31 is sealed. The exit end portion of the optical fiber 31 has a high light density and is likely to collect dust and easily deteriorate. However, the protection plate 63 can prevent the dust from adhering to the end face and delay the deterioration.
[0030]
In this example, in order to arrange the emission ends of the optical fibers 31 with a small cladding diameter in a line without any gaps, the multimode optical fiber 30 is placed between two adjacent multimode optical fibers 30 at a portion with a large cladding diameter. Two exit ends of the optical fiber 31 coupled to the two multimode optical fibers 30 adjacent to each other at the portion where the cladding diameter is large are the exit ends of the optical fiber 31 coupled to the stacked and stacked multimode optical fibers 30. They are arranged so that they are sandwiched between them.
[0031]
For example, as shown in FIG. 16, an optical fiber 31 having a length of 1 to 30 cm and having a small cladding diameter is coaxially provided at the tip of the multimode optical fiber 30 having a large cladding diameter. It can be obtained by bonding to. In the two optical fibers, the incident end face of the optical fiber 31 is fused and joined to the outgoing end face of the multimode optical fiber 30 so that the central axes of both optical fibers coincide. As described above, the diameter of the core 31 a of the optical fiber 31 is the same as the diameter of the core 30 a of the multimode optical fiber 30.
[0032]
In addition, a short optical fiber in which an optical fiber having a short cladding diameter and a large cladding diameter is fused to an optical fiber having a short cladding diameter and a large cladding diameter may be coupled to the output end of the multimode optical fiber 30 via a ferrule or an optical connector. Good. By detachably coupling using a connector or the like, the tip portion can be easily replaced when an optical fiber having a small cladding diameter is broken, and the cost required for exposure head maintenance can be reduced. Hereinafter, the optical fiber 31 may be referred to as an emission end portion of the multimode optical fiber 30.
[0033]
The multimode optical fiber 30 and the optical fiber 31 may be any of a step index type optical fiber, a graded index type optical fiber, and a composite type optical fiber. For example, a step index type optical fiber manufactured by Mitsubishi Cable Industries, Ltd. can be used. In the present embodiment, the multimode optical fiber 30 and the optical fiber 31 are step index type optical fibers, and the multimode optical fiber 30 has a cladding diameter = 125 μm, a core diameter = 25 μm, NA = 0.2, an incident end face. The transmittance of the coat is 99.5% or more, and the optical fiber 31 has a cladding diameter = 60 μm, a core diameter = 25 μm, and NA = 0.2.
[0034]
In general, in laser light in the infrared region, propagation loss increases as the cladding diameter of the optical fiber is reduced. For this reason, a suitable cladding diameter is determined according to the wavelength band of the laser beam. However, the shorter the wavelength, the smaller the propagation loss. In the case of laser light having a wavelength of 405 nm emitted from a GaN-based semiconductor laser, the cladding thickness {(cladding diameter−core diameter) / 2} is set to an infrared light having a wavelength band of 800 nm. The propagation loss hardly increases even if it is about ½ of the case of propagating infrared light and about ¼ of the case of propagating infrared light in the 1.5 μm wavelength band used for communication. Therefore, the cladding diameter can be reduced to 60 μm.
[0035]
However, the cladding diameter of the optical fiber 31 is not limited to 60 μm. The clad diameter of an optical fiber used in a conventional fiber light source is 125 μm, but the depth of focus becomes deeper as the clad diameter becomes smaller. Therefore, the clad diameter of a multimode optical fiber is preferably 80 μm or less, more preferably 60 μm or less. Preferably, it is 40 μm or less. On the other hand, since the core diameter needs to be at least 3 to 4 μm, the cladding diameter of the optical fiber 31 is preferably 10 μm or more.
[0036]
The laser module 64 is configured by a combined laser light source (fiber light source) shown in FIG. This combined laser light source includes a plurality of (for example, seven) chip-like lateral multimode or single mode GaN-based semiconductor lasers LD1, LD2, LD3, LD4, LD5, LD6, and the like fixed on the heat block 10. LD 7, collimator lenses 11, 12, 13, 14, 15, 16, and 17 provided corresponding to each of GaN-based semiconductor lasers LD 1 to LD 7, one condenser lens 20, and one multimode And an optical fiber 30. The number of semiconductor lasers is not limited to seven. For example, as many as 20 semiconductor laser beams can be incident on a multimode optical fiber having a cladding diameter = 60 μm, a core diameter = 50 μm, and NA = 0.2. In addition, the number of optical fibers can be further reduced.
[0037]
The GaN-based semiconductor lasers LD1 to LD7 all have the same oscillation wavelength (for example, 405 nm), and the maximum output is also all the same (for example, 100 mW for the multimode laser and 30 mW for the single mode laser). As the GaN-based semiconductor lasers LD1 to LD7, lasers having an oscillation wavelength other than the above 405 nm in a wavelength range of 350 nm to 450 nm may be used.
[0038]
As shown in FIGS. 18 and 19, the above combined laser light source is housed in a box-shaped package 40 having an upper opening together with other optical elements. The package 40 includes a package lid 41 created so as to close the opening thereof. After the deaeration process, a sealing gas is introduced, and the package 40 and the package lid 41 are closed by closing the opening of the package 40 with the package lid 41. The combined laser light source is hermetically sealed in a closed space (sealed space) formed by 41.
[0039]
A base plate 42 is fixed to the bottom surface of the package 40, and the heat block 10, a condensing lens holder 45 that holds the condensing lens 20, and the multimode optical fiber 30 are disposed on the top surface of the base plate 42. A fiber holder 46 that holds the incident end is attached. The exit end of the multimode optical fiber 30 is drawn out of the package through an opening formed in the wall surface of the package 40.
[0040]
Further, a collimator lens holder 44 is attached to the side surface of the heat block 10, and the collimator lenses 11 to 17 are held. An opening is formed in the lateral wall surface of the package 40, and wiring 47 for supplying a driving current to the GaN-based semiconductor lasers LD1 to LD7 is drawn out of the package through the opening. In FIG. 19, in order to avoid complication of the drawing, only the GaN semiconductor laser LD7 is numbered among the plurality of GaN semiconductor lasers, and only the collimator lens 17 is numbered among the plurality of collimator lenses. doing.
[0041]
FIG. 20 shows the front shape of the attachment part of the collimator lenses 11-17. Each of the collimator lenses 11 to 17 is formed in a shape obtained by cutting a region including the optical axis of a circular lens having an aspherical surface into a long and narrow plane. This elongated collimator lens can be formed, for example, by molding resin or optical glass. The collimator lenses 11 to 17 are closely arranged in the arrangement direction of the light emitting points so that the length direction is orthogonal to the arrangement direction of the light emitting points of the GaN-based semiconductor lasers LD1 to LD7 (left and right direction in FIG. 20).
[0042]
On the other hand, each of the GaN-based semiconductor lasers LD1 to LD7 includes an active layer having a light emission width of 2 μm, and each of the laser beams B1 in a state parallel to the active layer and a divergence angle in a direction perpendicular to the active layer, respectively, for example A laser emitting ~ B7 is used. These GaN-based semiconductor lasers LD1 to LD7 are arranged so that the light emitting points are arranged in a line in a direction parallel to the active layer. Accordingly, in the laser beams B1 to B7 emitted from the respective light emitting points, the direction in which the divergence angle is large coincides with the length direction and the divergence angle is small with respect to the elongated collimator lenses 11 to 17 as described above. Incident light is incident in a state where the direction coincides with the width direction (direction perpendicular to the length direction).
[0043]
That is, the collimator lenses 11 to 17 have a width of 1.1 mm and a length of 4.6 mm, and the horizontal and vertical beam diameters of the laser beams B1 to B7 incident thereon are 0.9 mm and 2. 6 mm. Each of the collimator lenses 11 to 17 has a focal length f. ₁ = 3 mm, NA = 0.6, and lens arrangement pitch = 1.25 mm.
[0044]
The condensing lens 20 is formed by cutting a region including the optical axis of a circular lens having an aspheric surface into a long and narrow shape in parallel planes, and is long in the arrangement direction of the collimator lenses 11 to 17, that is, in a horizontal direction and short in a direction perpendicular thereto. Is formed. The condenser lens 20 has a focal length f. ₂ = 23 mm, NA = 0.2. This condensing lens 20 is also formed by molding resin or optical glass, for example.
[0045]
Next, the operation of the exposure apparatus will be described. Lasers emitted in a divergent light state from each of the GaN-based semiconductor lasers LD1 to LD7 constituting the combined laser light source of the fiber array light source 66 in each exposure head 166 of the scanner 162. Each of the beams B1, B2, B3, B4, B5, B6, and B7 is collimated by the corresponding collimator lenses 11-17. The collimated laser beams B <b> 1 to B <b> 7 are collected by the condenser lens 20 and converge on the incident end face of the core 30 a of the multimode optical fiber 30.
[0046]
In this example, the collimator lenses 11 to 17 and the condenser lens 20 constitute a condensing optical system, and the condensing optical system and the multimode optical fiber 30 constitute a multiplexing optical system. That is, the laser beams B1 to B7 condensed as described above by the condenser lens 20 enter the core 30a of the multimode optical fiber 30 and propagate through the optical fiber to be combined with one laser beam B. The light is emitted from the optical fiber 31 coupled to the output end of the multimode optical fiber 30.
[0047]
In each laser module, when the coupling efficiency of the laser beams B1 to B7 to the multimode optical fiber 30 is 0.85 and each output of the GaN-based semiconductor lasers LD1 to LD7 is 30 mW, the light arranged in an array For each of the fibers 31, a combined laser beam B with an output of 180 mW (= 30 mW × 0.85 × 7) can be obtained. Therefore, the output from the laser emitting unit 68 in which the six optical fibers 31 are arranged in an array is about 1 W (= 180 mW × 6).
[0048]
In the laser emitting portion 68 of the fiber array light source 66, light emission points with high luminance are arranged in a line along the main scanning direction as described above. A conventional fiber light source that couples laser light from a single semiconductor laser to a single optical fiber has a low output, so a desired output could not be obtained unless multiple rows are arranged. Since the combined laser light source used in the form has a high output, a desired output can be obtained even with a small number of columns, for example, one column.
[0049]
For example, in a conventional fiber light source in which a semiconductor laser and an optical fiber are coupled on a one-to-one basis, a laser having an output of about 30 mW (milliwatt) is usually used as the semiconductor laser, and the core diameter is 50 μm and the cladding diameter is 125 μm. Since a multimode optical fiber having a numerical aperture (NA) of 0.2 is used, if an output of about 1 W (watt) is to be obtained, 48 multimode optical fibers (8 × 6) must be bundled. The area of the light emitting region is 0.62 mm ² (0.675 mm × 0.925 mm), the luminance at the laser emission unit 68 is 1.6 × 10 6. ⁶ (W / m ² ) The brightness per optical fiber is 3.2 × 10 ⁶ (W / m ² ).
[0050]
On the other hand, in this embodiment, as described above, an output of about 1 W can be obtained with six multimode optical fibers, and the area of the light emitting region at the laser emitting portion 68 is 0.0081 mm. ² (0.325 mm × 0.025 mm), the luminance at the laser emission unit 68 is 123 × 10. ⁶ (W / m ² Thus, the brightness can be increased by about 80 times compared to the conventional case. In addition, the luminance per optical fiber is 90 × 10 ⁶ (W / m ² The brightness can be increased by about 28 times compared to the conventional case.
[0051]
Here, with reference to FIGS. 21A and 21B, the difference in depth of focus between the conventional exposure head and the exposure head of the present embodiment will be described. The diameter of the bundled fiber light source emission region in the conventional exposure head in the sub-scanning direction is 0.675 mm, and the diameter of the fiber array light source emission region in the exposure head of this embodiment is 0.0025 mm. As shown in FIG. 21A, in the conventional exposure head, since the light emitting area of the light source (bundle-shaped fiber light source) 1 is large, the angle of the light beam incident on the DMD 3 increases, and as a result, the light beam enters the scanning surface 5. The angle of the light beam increases. For this reason, the beam diameter tends to increase with respect to the light condensing direction (shift in the focus direction).
[0052]
On the other hand, as shown in FIG. 21B, in the exposure head of this embodiment, the diameter of the light emission region of the fiber array light source 66 is small, so that the light flux that passes through the lens system 67 and enters the DMD 50 is shown. As a result, the angle of the light beam incident on the scanning surface 56 is reduced. That is, the depth of focus becomes deep. In this example, the diameter of the light emitting region in the sub-scanning direction is about 30 times that of the conventional one, and a depth of focus substantially corresponding to the diffraction limit can be obtained. Therefore, it is suitable for exposure of a minute spot. This effect on the depth of focus is more prominent and effective as the required light quantity of the exposure head is larger. In this example, the size of one pixel projected on the exposure surface is 10 μm × 10 μm. DMD is a reflective spatial modulation element, but FIGS. 21A and 21B are developed views for explaining the optical relationship.
[0053]
Image data corresponding to the exposure pattern is input to a controller (not shown) connected to the DMD 50 and temporarily stored in a frame memory in the controller. This image data is data representing the density of each pixel constituting the image by binary values (whether or not dots are recorded).
[0054]
The stage 152 having adsorbed the exposure material 150 on its surface is moved at a constant speed from the upstream side to the downstream side of the gate 160 along the guide 158 by a driving device (not shown). When the leading edge of the exposure material 150 is detected by the detection sensor 164 attached to the gate 160 while the stage 152 passes under the gate 160, the image data stored in the frame memory is sequentially read out for a plurality of lines. A control signal is generated for each exposure head 166 based on the image data read by the data processing unit. Then, each of the micromirrors of the DMD 50 is controlled on and off for each exposure head 166 based on the generated control signal by the mirror drive control unit.
[0055]
When the DMD 50 is irradiated with laser light from the fiber array light source 66, the laser light reflected when the micromirror of the DMD 50 is in the on state forms an image on the exposed surface 56 of the exposure material 150 by the lens systems 54 and 58. Is done. In this manner, the laser light emitted from the fiber array light source 66 is turned on / off for each pixel, and the exposure material 150 is exposed in approximately the same number of pixels (exposure area 168) as the number of used pixels of the DMD 50. Further, the exposure material 150 is moved at a constant speed together with the stage 152, so that the exposure material 150 is sub-scanned in the direction opposite to the stage moving direction by the scanner 162, and a strip-shaped exposed region 170 is formed for each exposure head 166. It is formed.
[0056]
As shown in FIGS. 22A and 22B, in this embodiment, the DMD 50 has 600 sets of micromirror arrays in which 800 micromirrors are arranged in the main scanning direction, which are arranged in the subscanning direction. However, in the present embodiment, control is performed so that only a part of micromirror rows (for example, 800 × 100 rows) are driven by the controller.
[0057]
As shown in FIG. 22 (A), a micromirror array arranged at the center of the DMD 50 may be used. As shown in FIG. 22 (B), the micromirror array arranged at the end of the DMD 50 may be used. May be used. In addition, when a defect occurs in some of the micromirrors, the micromirror array to be used may be appropriately changed depending on the situation, such as using a micromirror array in which no defect has occurred.
[0058]
Since the data processing speed of the DMD 50 is limited and the modulation speed per line is determined in proportion to the number of pixels used, the modulation speed per line can be increased by using only a part of the micromirror rows. Get faster. On the other hand, in the case of an exposure method in which the exposure head is continuously moved relative to the exposure surface, it is not necessary to use all the pixels in the sub-scanning direction.
[0059]
For example, when only 300 sets are used in 600 micromirror arrays, modulation can be performed twice as fast per line as compared to the case of using all 600 sets. Further, when only 200 sets of 600 micromirror arrays are used, modulation can be performed three times faster per line than when all 600 sets are used. That is, an area of 500 mm in the sub-scanning direction can be exposed in 17 seconds. Further, when only 100 sets are used, modulation can be performed 6 times faster per line. That is, an area of 500 mm in the sub-scanning direction can be exposed in 9 seconds.
[0060]
The number of micromirror rows to be used, that is, the number of micromirrors arranged in the sub-scanning direction is preferably 10 or more and 200 or less, and more preferably 10 or more and 100 or less. Since the area per micromirror corresponding to one pixel is 15 μm × 15 μm, when converted to the use area of DMD50, an area of 12 mm × 150 μm or more and 12 mm × 3 mm or less is preferable, and 12 mm × 150 μm or more and 12 mm A region of × 1.5 mm or less is more preferable.
[0061]
If the number of micromirror rows to be used is within the above range, as shown in FIGS. 23A and 23B, the laser light emitted from the fiber array light source 66 is made into substantially parallel light by the lens system 67, and the DMD 50 Can be irradiated. It is preferable that the irradiation area where the laser beam is irradiated by the DMD 50 coincides with the use area of the DMD 50. When the irradiation area is wider than the use area, the utilization efficiency of the laser light is lowered.
[0062]
On the other hand, the diameter of the light beam condensed on the DMD 50 in the sub-scanning direction needs to be reduced according to the number of micromirrors arranged in the sub-scanning direction by the lens system 67, but the number of micromirror rows to be used. Is less than 10, it is not preferable because the angle of the light beam incident on the DMD 50 increases and the depth of focus of the light beam on the scanning surface 56 becomes shallow. Further, the number of micromirror rows to be used is preferably 200 or less from the viewpoint of modulation speed. Note that DMD is a reflective spatial modulation element, but FIGS. 23A and 23B are developed views for explaining the optical relationship.
[0063]
When the sub scanning of the exposure material 150 by the scanner 162 is completed and the rear end of the exposure material 150 is detected by the detection sensor 164, the stage 152 is moved along the guide 158 by the driving device (not shown) on the most upstream side of the gate 160. Returned to the origin at the point, and again moved along the guide 158 from the upstream side to the downstream side of the gate 160 at a constant speed.
[0064]
The exposure apparatus as described above is, for example, the exposure of a dry film resist (DFR) in the manufacturing process of a printed wiring board (PWB) and the manufacture of a printed circuit board (PCB). Dry film resist (DFR) exposure in process, formation of color filter in liquid crystal display (LCD) manufacturing process, exposure of liquid resist in TFT manufacturing process, plasma display panel (PDP) Next, a modification of the exposure apparatus according to the present invention will be described.
[0065]
As shown in FIGS. 1 and 2, the exposure apparatus according to the present invention has a transparent glass plate stage 174 having a predetermined thickness (for example, 10 mm) arranged in an upright (vertical) state (a wide surface is front and back). Rails 178 are laid in parallel in the vertical direction on one side thereof and in the longitudinal direction of the stage 174 (sub-scanning direction). The pair of rails 178 includes a plurality of the above-described exposure heads 166 (configured to have a length equal to or greater than the width of the exposure material 148) and the line-shaped scanner 162 in the main scanning direction (the longitudinal direction of the stage 174). (In the orthogonal width direction) and supported so as to be movable in the left-right direction.
[0066]
Further, a roller 188 that is extendable in the front-rear direction by an actuator such as a cylinder 190 is disposed on the side opposite to the rail 178 with the stage 174 and the exposure material 148 interposed therebetween. Are fixed to the stage 174 when both ends thereof are pressed toward the stage 174 by the rollers 188. Since the stage 174 is arranged vertically, a separate support 192 may be provided so that the exposure material 148 is supported from below.
[0067]
In the exposure apparatus having such a configuration, as shown in FIG. 2, the laser light irradiated from the exposure head 166 in the main scanning direction passes through the transparent stage 174 and reaches the exposure surface of the exposure material 148. While moving along the rail 178 in the sub-scanning direction, the exposure surface is exposed by one scan, but the exposure surface is held upright by the stage 174, so that the exposure surface is dropped by gravity. Dust and the like do not adhere, and high yield exposure is possible. In addition, the stage and the exposure material are not warped or distorted by gravity. Needless to say, if the exposure head 166 (scanner 162) is disposed on the roller 188 side, the stage 174 need not be transparent.
[0068]
In this exposure apparatus, as shown in FIG. 3, the exposure material 148 can be configured to be exposed from both the front and back surfaces. That is, the stage 174 is made transparent, and the exposure head 166 (scanner 162) is disposed on the back side of the stage 174 (on the side opposite to the exposure material 148), and a pair is also provided on the front side where the roller 188 is provided. The rail 177 is laid substantially symmetrically with the rail 178, and a scanner 162 having an exposure head 166 is movably mounted on the rail 177.
[0069]
With such a configuration, the exposure material 148 can be simultaneously exposed from both the front and back surfaces, so that the exposure speed can be increased. Therefore, this exposure apparatus can be particularly suitably used for exposure of dry film resist (DFR) laminated on a printed circuit board (PCB) having a minimum line width of L / S = 50/50 μm, for example.
[0070]
That is, the laser light emitted from one exposure head 166 passes through the transparent stage 174 and is then applied to the DFR 148B on the substrate 148A, and the laser light emitted from the other exposure head 166 is directly applied to the substrate 148A. The DFR 148B is irradiated and moved in the sub-scanning direction along the rails 178 and 177, so that the exposure surface (DFR 148B) can be exposed simultaneously. Further, as an exposure material, not only a PCB substrate but also a thin (0.7 mm) glass substrate coated with a liquid resist for a liquid crystal color filter may be used. In this case, since the exposure is vertical, warping and distortion due to the gravity of the substrate can be similarly suppressed.
[0071]
The exposure apparatus shown in FIGS. 4 and 5 is configured such that the above-described exposure head 166 is disposed below the stage 172 and exposes the exposure material 146 from below. That is, a pair of rails 176 is disposed below the stage 172 disposed in a horizontal (horizontal) state (arranged so that the wide surface faces the vertical direction) and in the longitudinal direction of the stage 172 (sub-scanning direction). A linear scanner 162 (having a length longer than the width of the exposure material 146) provided with a plurality of exposure heads 166 across the main scanning direction is movably installed on the rail 176. .
[0072]
In addition, a pair of rollers 186 that hold down both ends of the exposure material 146 from above are suspended above the stage 172, and each roller 186 is configured to be movable up and down by an actuator such as a cylinder 190. Accordingly, the exposure material 146 is fixed by pressing both ends of the exposure material 146 toward the stage 172 by the roller 186 in the same manner as described above.
[0073]
The stage 172 is formed of a transparent glass plate having a predetermined thickness (for example, 10 mm), and also serves as the installation table 156 shown in FIG. 7, and is capable of transmitting laser light. Therefore, the laser beam irradiated from the exposure head 166 in the main scanning direction passes through the stage 172, is irradiated onto the exposure material 146, and moves along the rail 176 in the sub-scanning direction while moving the exposure surface 1 Exposure with one scan.
[0074]
In the case of such an exposure apparatus that exposes from the lower side, for example, it can be particularly suitably used for exposure of a liquid crystal color filter of the glass substrate 146A. That is, as shown in FIG. 5, the laser light that has passed through the stage 172 further passes through the glass substrate 146A on the stage 172, and exposes the liquid resist 146B applied to the upper surface of the glass substrate 146A. Since the lower surface side of the resist 146B at the boundary portion with the glass substrate 146A is exposed, a decrease in sensitivity due to oxygen inhibition is suppressed.
[0075]
That is, in the exposure apparatus that exposes from the upper side shown in FIG. 7, when exposing a liquid resist used for patterning a TFT and a liquid resist used for patterning a color filter, the sensitivity decreases due to oxygen inhibition ( In order to suppress (desensitization), it is preferable to expose the exposure material in a nitrogen atmosphere. By exposing in a nitrogen atmosphere, the oxygen inhibition of the photopolymerization reaction is suppressed, the resist becomes highly sensitive, and high-speed exposure is possible. However, in the case of exposing the boundary surface (exposure surface) with the glass substrate 146A with an exposure apparatus that exposes from below, oxygen is not originally present on the boundary surface (exposure surface). Even if it is not, reduction in sensitivity due to oxygen inhibition is suppressed, the capability of a high-speed exposure head can be extracted, and high-speed and large-area exposure can be realized. In addition, since the exposure surface faces downward, dust or the like does not adhere to the exposure surface due to dropping due to gravity, and uniform exposure with high yield is possible.
[0076]
Also in this case, as shown in FIG. 6, a pair of rails (not shown) are laid on the upper side of the rail 176 so as to be substantially symmetrical in the vertical direction, and the scanner 162 having the exposure head 166 can be moved to the upper rail. If installed, both sides can be exposed simultaneously even in the horizontal type, so that the exposure speed can be increased.
[0077]
In the embodiment shown in FIGS. 1 to 6, the exposure apparatus is configured to move the scanner 162 (exposure head 166) for exposure, but the stages 172 and 174 are arranged in the same manner as shown in FIG. Needless to say, it may be configured to be movable. In the case of the vertical installation type, if the scanner 162 is constructed so as to be installed in the longitudinal direction of the stage 174 and moved in the vertical direction, a power failure or the like occurs while the scanner 162 is waiting upward, and the power is off. Then, the scanner 162 (exposure head 166) is constructed in the vertical direction and moved in the horizontal direction (left-right direction) as shown in the drawing because there is a risk of falling and causing an accident. Is preferred. With this configuration, there is no risk of dropping due to the structure.
[0078]
In this way, the scanner 162 (exposure head 166) is not moved in two directions (vertical and horizontal directions), but is formed in a line extending in the main scanning direction (with a length longer than the width of the exposure materials 146 and 148). If it is configured to move only in one direction (lateral direction) by guide members such as rails 176 to 178, exposure can be performed by one scan in the sub-scanning direction. In the case of double-sided simultaneous exposure, the movement of one scanner 162 is less likely to be affected by the vibration generated by one scanner 162 during movement. In this way, it is possible to obtain an exposure apparatus that is excellent in vibration resistance while being structurally inexpensive.
[0079]
In any case, the exposure apparatus of this embodiment includes a DMD in which 600 sets of micromirror arrays in which 800 micromirrors are arranged in the main scanning direction are arranged in the subscanning direction. Since control is performed so that only a part of the micromirror rows are driven, the modulation speed per line becomes faster than when all the micromirror rows are driven. This enables high-speed exposure.
[0080]
Further, since a high-intensity fiber array light source in which output ends of optical fibers of a combined laser light source are arranged in an array is used as a light source for illuminating the DMD, an exposure apparatus having a high output and a deep focal depth Can be realized. Furthermore, since the output of each fiber light source is increased, the number of fiber light sources necessary to obtain a desired output is reduced, and the cost of the exposure apparatus can be reduced.
[0081]
In particular, in the present embodiment, since the cladding diameter of the output end of the optical fiber is made smaller than the cladding diameter of the incident end, the diameter of the light emitting section is further reduced, and the brightness of the fiber array light source can be increased. Thereby, an exposure apparatus having a deeper depth of focus can be realized. For example, even in the case of ultra-high resolution exposure with a beam diameter of 1 μm or less and a resolution of 0.1 μm or less, a deep depth of focus can be obtained without distortion over the entire exposure region, and high-speed and high-definition exposure is possible. . Therefore, it is suitable for a thin film transistor (TFT) exposure process that requires high resolution.
[0082]
Furthermore, the above exposure apparatus can be used for various laser processing such as laser ablation, sintering, and lithography in which a part of the material is removed by evaporation, scattering, etc. by laser irradiation. The above exposure apparatus has a high output and can be exposed at a high speed and a long focal depth, so that it can be used for fine processing such as laser ablation. For example, instead of performing development processing, the resist is removed according to a pattern by ablation to create a PWB, or the above exposure apparatus can be used to form a PWB pattern by ablation directly without using a resist. it can. It can also be used to form microchannels with a groove width of several tens of μm in a lab-on-chip in which many solutions are mixed, reacted, separated, detected, etc. on glass or plastic chips.
[0083]
In particular, the exposure apparatus described above uses a GaN-based semiconductor laser as a fiber array light source, and therefore can be suitably used for the laser processing described above. That is, the GaN-based semiconductor laser can be driven with a short pulse, and sufficient power can be obtained for laser ablation and the like. In addition, since it is a semiconductor laser, it can be driven at a high repetition rate of about 10 MHz unlike a solid-state laser having a low driving speed, and high-speed exposure is possible. Furthermore, since metal has a large light absorption rate of laser light having a wavelength of around 400 nm and can be easily converted into thermal energy, laser ablation and the like can be performed at high speed.
[0084]
The exposure apparatus can use either a photon mode exposure material in which information is directly recorded by exposure or a heat mode exposure material in which information is recorded by heat generated by exposure. When a photon mode exposure material is used, a GaN-based semiconductor laser, a wavelength conversion solid-state laser, or the like is used for the laser device. When a heat mode exposure material is used, an AlGaAs-based semiconductor laser (infrared laser) is used for the laser device. A solid state laser is used.
[0085]
In the above embodiment, the example in which the DMD micromirror is partially driven has been described. However, the length of the direction corresponding to the predetermined direction is controlled on the substrate longer than the length of the direction intersecting the predetermined direction. Even if a long and thin DMD in which a number of micromirrors that can change the angle of the reflecting surface according to the signal are arranged in two dimensions is used, the number of micromirrors that control the angle of the reflecting surface is reduced. Speed can be increased.
[0086]
In the above-described embodiment, the exposure head provided with the DMD as the spatial modulation element has been described. For example, a MEMS (Micro Electro Mechanical Systems) type spatial modulation element (SLM), or transmission using an electro-optic effect is possible. Even when a spatial modulation element other than the MEMS type, such as an optical element (PLZT element) that modulates light or a liquid crystal optical shutter (FLC), is used, a part of the pixel parts is compared with all the pixel parts arranged on the substrate. By using, it is possible to increase the modulation speed per pixel and per main scanning line, so the same effect can be obtained.
[0087]
Note that MEMS is a general term for micro systems that integrate micro-sized sensors, actuators, and control circuits based on micro-machining technology based on the IC manufacturing process. It means a spatial modulation element that is driven by the electromechanical operation used.
[0088]
In the above embodiment, as shown in FIG. 24, the entire surface of the exposure material 150 may be exposed by one scan in the X direction by the scanner 162, as shown in FIGS. 25 (A) and 25 (B). In addition, after scanning the exposure material 150 in the X direction by the scanner 162, the scanner 162 is moved one step in the Y direction, and scanning is performed in the X direction. The entire surface of the material 150 may be exposed. In this example, the scanner 162 includes 18 exposure heads 166.
[0089]
In the above embodiment, an example using a fiber array light source including a plurality of combined laser light sources has been described. However, the laser device is not limited to a fiber array light source in which combined laser light sources are arrayed. For example, a fiber array light source obtained by arraying fiber light sources including one optical fiber that emits laser light incident from a single semiconductor laser having one light emitting point can be used.
[0090]
As a light source having a plurality of light emitting points, for example, as shown in FIG. 26, a laser array in which a plurality of (for example, seven) chip-shaped semiconductor lasers LD1 to LD7 are arranged on a heat block 100 is used. be able to. Further, a chip-shaped multicavity laser 110 shown in FIG. 27A in which a plurality of (for example, five) light emitting points 110a are arranged in a predetermined direction is known. Since the multicavity laser 110 can arrange the light emitting points with higher positional accuracy than the case where the chip-shaped semiconductor lasers are arranged, it is easy to multiplex laser beams emitted from the respective light emitting points. However, as the number of light emitting points increases, the multicavity laser 110 is likely to be bent at the time of laser manufacturing. Therefore, the number of light emitting points 110a is preferably 5 or less.
[0091]
In the exposure head of this embodiment, as shown in FIG. 27B, the multi-cavity laser 110 and the plurality of multi-cavity lasers 110 on the heat block 100 have the same arrangement direction of the light emitting points 110a of each chip. A multicavity laser array arranged in a direction can be used as a laser device (light source).
[0092]
The combined laser light source is not limited to one that combines laser beams emitted from a plurality of chip-shaped semiconductor lasers. For example, as shown in FIG. 28, a combined laser light source including a chip-shaped multicavity laser 110 having a plurality of (for example, three) emission points 110a can be used. This combined laser light source is configured to include a multi-cavity laser 110, one multi-mode optical fiber 130, and a condensing lens 120. The multi-cavity laser 110 can be composed of, for example, a GaN-based laser diode having an oscillation wavelength of 405 nm.
[0093]
In the above configuration, each of the laser beams B emitted from each of the plurality of light emitting points 110 a in the multicavity laser 110 is collected by the condenser lens 120 and enters the core 130 a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted.
[0094]
A plurality of light emitting points 110 a of the multi-cavity laser 110 are juxtaposed within a width substantially equal to the core diameter of the multi-mode optical fiber 130, and a focal point substantially equal to the core diameter of the multi-mode optical fiber 130 is used as the condenser lens 120. By using a convex lens of a distance and a rod lens that collimates the outgoing beam from the multi-cavity laser 110 only in a plane perpendicular to the active layer, the coupling efficiency of the laser beam B to the multi-mode optical fiber 130 can be increased. it can.
[0095]
29, a multi-cavity laser 110 having a plurality of (for example, three) emission points is used, and a plurality of (for example, nine) multi-cavity lasers 110 are equally spaced from each other on the heat block 111. A combined laser light source including the laser array 140 arranged in (1) can be used. The plurality of multi-cavity lasers 110 are arranged and fixed in the same direction as the arrangement direction of the light emitting points 110a of each chip.
[0096]
This combined laser light source includes a laser array 140, a plurality of lens arrays 114 arranged corresponding to each multi-cavity laser 110, and a single rod arranged between the laser array 140 and the plurality of lens arrays 114. The lens 113, one multimode optical fiber 130, and a condenser lens 120 are provided. The lens array 114 includes a plurality of microlenses corresponding to the emission points of the multicavity laser 110.
[0097]
In the above configuration, each of the laser beams B emitted from each of the plurality of light emitting points 10a in the plurality of multi-cavity lasers 110 is condensed in a predetermined direction by the rod lens 113, and then each microlens of the lens array 114. It becomes parallel light. The collimated laser beam L is condensed by the condenser lens 120 and enters the core 130a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted.
[0098]
Still another example of the combined laser light source will be described. In this combined laser light source, as shown in FIGS. 30A and 30B, a heat block 182 having an L-shaped cross section in the optical axis direction is mounted on a substantially rectangular heat block 180, and two heats are provided. A storage space is formed between the blocks. On the upper surface of the L-shaped heat block 182, a plurality of (for example, two) multi-cavity lasers 110 in which a plurality of light emitting points (for example, five) are arranged in an array form the light emitting points 110a of each chip. It is arranged and fixed at equal intervals in the same direction as the arrangement direction.
[0099]
A concave portion is formed in the substantially rectangular heat block 180, and a plurality of (for example, two) light emitting points (for example, five) are arranged in an array on the upper surface of the space side of the heat block 180. The multi-cavity laser 110 is arranged such that its emission point is located on the same vertical plane as the emission point of the laser chip arranged on the upper surface of the heat block 182.
[0100]
On the laser beam emission side of the multi-cavity laser 110, a collimator lens array 184 in which collimator lenses are arranged corresponding to the light emission points 110a of the respective chips is arranged. In the collimating lens array 184, the length direction of each collimating lens coincides with the direction in which the divergence angle of the laser beam is large (the fast axis direction), and the width direction of each collimating lens is in the direction in which the divergence angle is small (slow axis direction). They are arranged to match. Thus, collimating lenses are integrated into an array to improve the space utilization efficiency of the laser beam, increase the output of the combined laser light source, reduce the number of parts, and reduce the cost. Can do.
[0101]
Further, on the laser beam emitting side of the collimating lens array 184, there is one multimode optical fiber 130, and a condensing lens 120 that condenses and combines the laser beam at the incident end of the multimode optical fiber 130. Has been placed. In the above configuration, each of the laser beams B emitted from each of the plurality of light emitting points 10a in the plurality of multicavity lasers 110 arranged on the laser blocks 180 and 182 is collimated by the collimating lens array 184 and collected. The light is condensed by the optical lens 120 and is incident on the core 130 a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted.
[0102]
As described above, this combined laser light source can achieve particularly high output by the multi-stage arrangement of multi-cavity lasers and the array of collimating lenses. By using this combined laser light source, a higher-intensity fiber array light source or bundle fiber light source can be formed, which is particularly suitable as a fiber light source constituting the laser light source of the exposure apparatus of the present invention. It should be noted that a laser module in which each of the above combined laser light sources is housed in a casing and the emission end portion of the multimode optical fiber 130 is pulled out from the casing can be configured.
[0103]
In the above embodiment, another optical fiber having the same core diameter as the multimode optical fiber and a cladding diameter smaller than the multimode optical fiber is coupled to the output end of the multimode optical fiber of the combined laser light source. However, for example, a multimode optical fiber having a cladding diameter of 125 μm, 80 μm, 60 μm, or the like can be used without coupling another optical fiber to the output end. Good.
[0104]
In the above embodiment, two sets of lenses are arranged as the imaging optical system on the light reflection side of the DMD used for the exposure head. However, an imaging optical system for enlarging the laser beam to form an image is arranged. May be. By expanding the cross-sectional area of the light beam reflected by the DMD, the exposure area area (image area) on the exposed surface can be expanded to a desired size.
[0105]
For example, as shown in FIG. 31A, the exposure head is configured to illuminate the DMD 50, the illumination device 144 that irradiates the DMD 50 with laser light, the lens systems 454, 458, and the DMD 50 that expand and image the laser light reflected by the DMD 50. A microlens array 472 in which a large number of microlenses 474 are arranged corresponding to each of the pixels, an aperture array 476 in which a large number of apertures 478 are provided corresponding to each microlens of the microlens array 472, and a laser that has passed through the aperture It can be configured by lens systems 480 and 482 that form an image of light on the exposed surface 56.
[0106]
In this exposure head, when laser light is irradiated from the illumination device 144, the cross-sectional area of the light beam reflected by the DMD 50 in the ON direction is enlarged several times (for example, twice) by the lens systems 454 and 458. . The expanded laser light is condensed corresponding to each pixel of the DMD 50 by each microlens of the microlens array 472, and passes through the corresponding aperture of the aperture array 476. The laser light that has passed through the aperture is imaged on the exposed surface 56 by the lens systems 480 and 482.
[0107]
In this imaging optical system, the laser light reflected by the DMD 50 is magnified several times by the magnifying lenses 454 and 458 and projected onto the exposed surface 56, so that the entire image area is widened. At this time, if the microlens array 472 and the aperture array 476 are not arranged, as shown in FIG. 31B, one pixel size (spot size) of each beam spot BS projected onto the exposed surface 56 is exposed. MTF (Modulation Transfer Function) characteristics representing the sharpness of the exposure area 468 are reduced depending on the size of the area 468.
[0108]
On the other hand, when the microlens array 472 and the aperture array 476 are arranged, the laser light reflected by the DMD 50 is condensed corresponding to each pixel of the DMD 50 by each microlens of the microlens array 472. Thereby, as shown in FIG. 31C, even when the exposure area is enlarged, the spot size of each beam spot BS can be reduced to a desired size (for example, 10 μm × 10 μm), and the MTF characteristic is obtained. It is possible to perform high-definition exposure while preventing a decrease in the image quality. The exposure area 468 is tilted because the DMD 50 is tilted to eliminate a gap between pixels.
[0109]
In addition, even if the beam is thick due to the aberration of the microlens, the beam can be shaped by the aperture so that the spot size on the exposed surface 56 becomes a constant size, and corresponding to each pixel. By passing the provided aperture, it is possible to prevent crosstalk between adjacent pixels. Furthermore, by using a high-intensity light source for the illumination device 144 as in the above embodiment, the angle of the light beam incident on each microlens of the microlens array 472 from the lens 458 is reduced, so that the light flux of adjacent pixels can be reduced. Part of the incident can be prevented. That is, a high extinction ratio can be realized.
[0110]
【The invention's effect】
As described above, according to the present invention, dust or the like does not adhere to the exposure surface, and therefore no failure occurs. In addition, since the double-sided simultaneous exposure is possible, the exposure speed can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing the appearance of an exposure apparatus in which an exposure head is installed below.
FIG. 2 is a schematic side view of the above.
FIG. 3 is a schematic perspective view showing the appearance of an exposure apparatus in which an exposure head is installed on the side.
FIG. 4 is a schematic side view of the above.
FIG. 5 is a schematic side view showing an appearance of an exposure apparatus in which an exposure head is installed on both sides of an exposure material.
FIG. 6 is a schematic side view showing the appearance of an exposure apparatus in which exposure heads are installed below and above the exposure material.
FIG. 7 is a perspective view showing the appearance of a conventional exposure apparatus.
FIG. 8 is a perspective view showing a configuration of a scanner of the exposure apparatus.
FIG. 9A is a plan view showing an exposed region formed on an exposure material.
(B) A diagram showing the arrangement of exposure areas by each exposure head
FIG. 10 is a perspective view showing a schematic configuration of an exposure head of the exposure apparatus.
11A is a cross-sectional view in the sub-scanning direction along the optical axis showing the configuration of the exposure head shown in FIG.
(B) Side view of (A)
FIG. 12 is a partially enlarged view showing a configuration of a digital micromirror device (DMD).
FIG. 13A is an explanatory diagram for explaining the operation of the DMD.
(B) Explanatory diagram for explaining the operation of the DMD
FIG. 14A is a plan view showing the arrangement of exposure beams and scanning lines in a case where the DMD is not inclined and in a case where the DMD is inclined.
(B) A plan view showing the arrangement of the exposure beam and the scanning line in a case where the DMD is not inclined and in a case where the DMD is inclined.
FIG. 15A is a perspective view showing the configuration of a fiber array light source.
(B) Partial enlarged view of (A)
(C) Plan view showing the arrangement of light emitting points in the laser emitting section
(D) A plan view showing an array of light emitting points in the laser emitting section
FIG. 16 is a diagram showing the configuration of a multimode optical fiber
FIG. 17 is a plan view showing the configuration of a combined laser light source.
FIG. 18 is a plan view showing the configuration of a laser module.
19 is a side view showing the configuration of the laser module of FIG. 18;
20 is a partial side view showing the configuration of the laser module of FIG. 18;
FIG. 21A is a sectional view along the optical axis showing the difference between the depth of focus in the conventional exposure apparatus and the depth of focus in the exposure apparatus according to the present embodiment;
(B) Sectional view along the optical axis showing the difference between the depth of focus in the conventional exposure apparatus and the depth of focus in the exposure apparatus according to the present embodiment
FIG. 22A is a diagram showing an example of a DMD usage area;
(B) Diagram showing examples of DMD usage areas
FIG. 23A is a side view when the DMD usage area is appropriate.
(B) Sectional view in the sub-scanning direction along the optical axis of (A)
FIG. 24 is a plan view for explaining an exposure method for exposing an exposure material by one scanning by a scanner.
FIG. 25A is a plan view for explaining an exposure method in which an exposure material is exposed by scanning a plurality of times by a scanner.
(B) The top view for demonstrating the exposure system which exposes an exposure material by the multiple times of scanning by a scanner
FIG. 26 is a perspective view showing the configuration of a laser array.
FIG. 27A is a perspective view showing the configuration of a multi-cavity laser.
(B) Perspective view of a multi-cavity laser array in which the multi-cavity lasers shown in (A) are arranged in an array.
FIG. 28 is a plan view showing another configuration of the combined laser light source.
FIG. 29 is a plan view showing another configuration of the combined laser light source.
FIG. 30A is a plan view showing another configuration of the combined laser light source.
(B) Sectional view along the optical axis of (A)
FIG. 31A is a cross-sectional view along the optical axis showing the configuration of another exposure head having a different coupling optical system;
(B) A plan view showing a light image projected on a surface to be exposed when a microlens array or the like is not used.
(C) Plan view showing a light image projected on the exposed surface when a microlens array or the like is used.
[Explanation of symbols]
146-150 exposure material
152, 172, 174 stages
162 Scanner
166 Exposure head
168 Exposure area
170 Exposed area
176-178 rail

Claims (5)

A base for erecting the exposure surface of the exposure material held;
An exposure head that moves relative to the base and exposes an exposure surface according to image data;
Scanning means for moving the base or the exposure head on an upright surface;
An exposure apparatus comprising: The exposure apparatus according to claim 1, wherein the base is transparent, and the exposure head exposes an exposure material from the back side of the base. The exposure apparatus according to claim 2, wherein the exposure head is also provided on the front side of the base and exposes the exposure material from both the front and back sides. A transparent base that horizontally supports the exposure surface of the exposure material to be held;
An exposure head that moves relative to the base and exposes an exposure surface according to image data;
Scanning means for moving the base or the exposure head on a horizontal plane;
With
An exposure apparatus, wherein the exposure head exposes an exposure material from the back side of a base. 5. The exposure apparatus according to claim 4, wherein the exposure head is also provided on the front side of the base and exposes the exposure material from both the front and back sides.

Images