JP2006098719A - Exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To expose the entire exposure region as a curved face, with high accuracy on a curved face of a flexible recording medium located on a drum surface. <P>SOLUTION: The entire three-dimensional exposure region on the arc curved surface of a flexible recording medium 12 traveling along the surface of a drum 10 driven to rotate is exposed to a light beam for exposure, projected from an exposure head 14. In this process, the exposure light beam projected from the exposure head 14 is focused for imaging over the entire three-dimensional exposure region on the arc curved surface of the flexible recording medium 12, traveling along the drum 10 to carry out appropriate exposure process. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  According to the present invention, a projected image by a light beam modulated based on image data (pattern data) by a spatial light modulator (two-dimensional light modulator) or the like installed in an exposure head is placed on a curved surface of a rotating drum. The present invention relates to an exposure apparatus that exposes a long flexible recording medium that is continuously conveyed along a predetermined pattern by irradiating the flexible recording medium.

  Among exposure apparatuses that are generally used, there are exposure apparatuses such as a scanning type printed board exposure apparatus, a laser photo plotter, and a laser printer that draw a desired image on a recording medium by scanning a recording medium with a light beam. .

  In such an exposure apparatus, for example, in the case of a printed circuit board exposure apparatus, drawing is performed by scanning a laser beam on a substrate material for a printed wiring board that is a recording medium. The substrate material for a printed wiring board used here is formed by forming a conductive thin film on an insulating layer and coating the conductive thin film with a photoresist.

  This printed circuit board exposure apparatus scans the substrate material with a laser beam modulated based on image data, thereby exposing a desired substrate pattern to the photoresist layer.

  The substrate material for the printed wiring board thus exposed is removed from the printed board exposure apparatus and further subjected to photoetching to complete a printed board.

  In the conventional printed circuit board exposure apparatus used in this way, a long strip-shaped recording medium is stretched between a loader for feeding out a roll sheet-shaped recording medium and an unloader for collecting the recording medium. The drawing table is configured to be slidable with high precision by the sliding means in a state where the stretched portion of the recording medium is placed and fixed on the drawing surface of the drawing table by the fixing means. Further, a scanning optical system that scans the laser beam is disposed immediately above the recording medium stretched between the loader and the unloader.

  The scanning optical system slides with the drawing table with high accuracy while the drawing table in which the stretched portion of the recording medium is fixed on the drawing surface by the fixing unit is conveyed with high accuracy by the sliding unit. Drawing is performed by scanning a laser beam modulated on the basis of image data on a moving medium.

  Further, in this conventional printed circuit board exposure apparatus, the drawing process is started again after the first drawing process is completed, so that the drawing table fixing means is released, the recording medium is fixed by the clamp roller pair of the loader, and the unloader The drawing table is moved to the loader side by the slide means after the recording medium fixed between the drive roller pair is fixed and the recording medium stretched between the loader and the unloader is set in a stationary state. Next, the recording medium is fixed on the drawing surface of the drawing table by the drawing table fixing means. Next, the clamp roller pair of the loader is opened, and the recording medium is fed out by the loader feeding roller pair to form a slack. Next, while the drawing table is moved to the unloader side by the sliding means, the recording medium fixed on the drawing surface of the drawing table is scanned by the scanning optical system, and the recording medium is moved by the pair of driving rollers of the unloader. The next drawing process is completed after collecting in the unloader. In addition, when performing the next drawing process, the above-described operation is repeated as many times as necessary (see, for example, Patent Document 1).

In such a conventional printed circuit board exposure apparatus, from the end of the drawing process to the start of the next drawing process, the drawing table fixing means is released, the recording medium is fixed by the loader and the unloader, and the sliding means Then, the drawing table is moved to the loader side, the recording medium is fixed on the drawing surface of the drawing table by the drawing table fixing means, the clamp roller pair of the loader is opened, and the recording medium is set by the pair of feeding rollers of the loader. Since the next drawing operation cannot be performed until the operation for forming the slack is completed, the waiting time other than the exposure processing time is increased, resulting in a problem that the productivity is lowered.
JP 2000-235267 A

  In view of the above-described problems, the present invention makes it possible to perform exposure processing with high accuracy on the entire exposure area that is a curved surface of a flexible recording medium on a drum surface, and to make a long flexible film. The recording medium is continuously conveyed along the curved surface of the rotating drum so that the curved surface of the flexible recording medium on the drum surface can be continuously exposed. Thus, an object of the present invention is to newly provide an exposure apparatus that can reduce the waiting time and perform a lot of exposure processing in a short time to improve productivity.

  According to a first aspect of the present invention, there is provided an exposure apparatus comprising: a drum that is rotationally driven in a state in which a flexible recording medium is placed along a surface; and an incident light beam that is image data corresponding to a predetermined exposure area on a plane. 3D on an arc curved surface of a flexible recording medium along a drum, with an exposure head provided with a two-dimensional light modulator that modulates each pixel in accordance with the exposure light beam and an exposure light beam projected from the exposure head Focal length adjusting means for focusing and forming an image over the entire exposure area.

  According to a second aspect of the present invention, in the exposure apparatus according to the first aspect, the two-dimensional optical modulator is constituted by a digital micromirror device (DMD).

  According to a third aspect of the present invention, in the exposure apparatus according to the first or second aspect, the focal length adjusting means is provided with a microlens in which each focal position matches an arcuate curved surface of the flexible recording medium. It is characterized by comprising a microlens array.

  According to a fourth aspect of the present invention, in the exposure apparatus according to the third aspect, the microlens array has all the microlenses arranged in a plane, and the focal length of each microlens is set to the arc of the flexible recording medium. It is characterized by being configured to coincide with a curved surface.

  According to a fifth aspect of the present invention, in the exposure apparatus according to the third aspect, the microlens array makes the focal length of all the microlenses constant, and the length of the focal length from the arcuate curved surface of the flexible recording medium. It is configured to be positioned on a parallel arcuate curved surface placed.

  According to a sixth aspect of the present invention, in the exposure apparatus according to the first or second aspect, the focal length adjusting means is a two-dimensional exposure region in which the exposure light beam projected from the projection optical system of the exposure head is two-dimensional. The image is formed with a cylindrical lens that changes the image so as to form an image on a three-dimensional exposure region that is an arc curved surface of a flexible recording medium.

  By configuring as described above, the exposure process can be appropriately performed by focusing and forming an image over the entire three-dimensional exposure area on the arcuate curved surface of the flexible recording medium along the surface of the drum. Can do. In addition, when the long flexible recording medium is continuously conveyed by the drum driven by rotation and the exposure process is always continued, the waiting time is reduced and many exposure processes are performed in a short time. Can improve productivity. Furthermore, since the flexible recording medium can be transported and exposed while being stably held by being wound around the drum, the stability of the exposure process can be improved.

  According to the exposure apparatus of the present invention, it is possible to perform exposure processing with high accuracy on the entire exposure area that is a curved surface of the flexible recording medium on the drum surface, and to make a long flexible recording medium. Is continuously conveyed in a state along the curved surface of the rotating drum, it is possible to continuously expose the curved surface of the flexible recording medium on the drum surface. There is an effect that the waiting time can be reduced and productivity can be improved by performing many exposure processes in a short time.

  An embodiment relating to an exposure apparatus of the present invention will be described with reference to FIGS.

  The exposure apparatus according to the embodiment of the present invention, as shown in FIG. 1, includes a flexible printed wiring board material 12 that is a flexible recording medium that is automatically controlled by a control unit and formed on a long belt-like sheet. A plurality of exposure heads 14 are emitted from the light source side based on the modulation signal generated from the image data by the plurality of exposure heads 14 while being conveyed in the main scanning direction along the outer peripheral surface of the drum 10 that is rotationally driven. The exposed multi-beam is spatially modulated and irradiated onto the flexible printed wiring board material 12 to constitute an exposure apparatus that performs an exposure process.

  As shown in FIG. 1, in this exposure apparatus, an exposure processing unit 11 is arranged at the center of the apparatus main body, and unexposed recording is performed on one side (left side as viewed in FIG. 1) of the exposure processing unit 11. A medium supply unit is arranged, and an exposed recording medium collection unit is arranged on the other side (right side as viewed in FIG. 1) of the exposure processing unit 11.

  The unexposed recording medium supply unit includes a supply reel 60 around which an unexposed long flexible printed wiring board material 12 is wound and a spacer tape take-up reel (not shown) as a drive unit (not shown). Install and configure.

  In this unexposed recording medium supply unit, the flexible printed wiring board material 12 pulled out from the supply reel 60 can be conveyed by rotating the drum 10 in a state of being in close contact with the outer peripheral surface of the drum 10. It is configured to be carried into the entrance of the recording medium conveyance path of the exposure processing unit 11 via a dancer roller mechanism that is a tension setting means for this purpose.

  For example, the dancer roller mechanism is configured such that the flexible printed wiring board material 12 is loosened in a U shape between the exit side roller 66 of the unexposed recording medium supply unit and the guide roller 62 of the exposure processing unit 11. The roller 68 is mounted and configured to roll. The dancer roller mechanism can be replaced by a so-called air dancer configured to suck the flexible printed wiring board material 12 with air.

  In the unexposed recording medium supply unit configured as described above, the drive unit rotates the supply reel 60 to draw out the flexible printed wiring board material 12 and the outer peripheral surface of the drum 10 of the exposure processing unit 11 via the dancer roller mechanism. It is configured so as to be continuously supplied on a transport path passing through the top.

  Although not shown, the supply reel 60 is wound with a spacer tape sandwiched between the wound flexible printed wiring board members 12 so as not to directly contact each other. For this reason, in the unexposed recording medium supply unit, the drive unit rotates the spacer tape take-up reel so that the spacer tape extending together with the flexible printed wiring board material 12 to be carried out is taken up on the spacer tape take-up reel. To do.

  Further, the exposed recording medium recovery unit disposed on the downstream side in the transport direction from the exposure processing unit 11 includes a take-up reel 70 around which the exposed long flexible printed wiring board material 12 is wound, and a spacer tape supply reel ( And a drive unit (not shown).

  In the exposed recording medium recovery unit, the exposed flexible print carried out from the exposure processing unit 11 via a dancer roller mechanism as tension setting means connected to the exit of the recording medium conveyance path of the exposure processing unit 11. The wiring board material 12 is wound around the take-up reel 70.

  In this dancer roller mechanism, for example, the flexible printed wiring board material 12 is U-shaped between a holding roller 76 arranged on the downstream side in the transport direction of the exposure processing unit 11 and an entrance side roller 78 of the exposed recording medium recovery unit. The dancer roller 68 is placed so as to roll on the slackened portion.

  The exposed recording medium recovery unit configured as described above allows the flexible printed wiring board material 12 sent out from the exposure processing unit 11 via the dancer roller mechanism by rotating the take-up reel 70 by the drive unit. It is configured to be continuously wound and collected.

  Further, in the exposed recording medium collecting unit, although not shown, when winding on the take-up reel 70, the flexible printed wiring board materials 12 wound on the take-up reel 70 are not directly in contact with each other. A spacer tape is sandwiched between the winding surfaces and wound. Therefore, in the exposed recording medium collection unit, the spacer tape supply reel is pulled out from the spacer tape supply reel by the drive unit so that the spacer tape can be wound around the flexible printed wiring board material 12 to be loaded. Rotate.

  The flexible printed wiring board material 12 carried in from the unexposed recording medium supply unit is wound around the exposure processing unit 11 disposed in the center of the exposure apparatus main body so as to be along the outer peripheral surface of the drum 10, A conveying path is set in synchronization with the rotational driving operation of the drum 10 to reach the exposed recording medium collecting unit.

  In the exposure processing unit 11, an alignment unit 80 is disposed at an upper position upstream in the transport direction of the transport path, and an exposure head unit 82 as a drawing unit is disposed downstream in the transport direction.

  Although not shown, the alignment unit 80 is installed with a base portion 84 attached to a fixed structure portion such as a casing of an exposure apparatus. The base portion 84 is provided with a pair of parallel rail portions (not shown), and a lens at a desired position in the width direction of the flexible printed wiring board material 12 via a camera base that is moved by a ball screw mechanism. A plurality (four in this embodiment) of camera units 86 are mounted so as to be movable so that the optical axes of the units are aligned.

  Although not shown, each camera unit 86 is provided with a lens unit on the lower surface of the camera body, and a ring-shaped strobe light source (LED strobe light source) is attached to the protruding tip of the lens unit. The camera unit 86 irradiates the flexible printed wiring board material 12 with light from the strobe light source, and the reflected light is captured by the camera body through the lens unit. Edges or marks (not shown) are detected.

  Although not shown, the exposure head unit 82 as a drawing unit arranged in the exposure processing unit 11 shown in FIG. 1 is a column that is erected on the outside of both ends in the width direction of the flexible printed wiring board material 12 being conveyed. Install and install on.

  The exposure head unit 82 as the drawing unit is configured as a laser exposure apparatus, and a plurality of exposure heads 14 are arranged in a substantially matrix shape of m rows and n columns (for example, 2 rows and 4 columns in total), The rows of the plurality of exposure heads 14 correspond to the width direction of the flexible printed wiring board material 12 (the direction perpendicular to the conveying direction and the direction perpendicular to the scanning direction that is the conveying direction of the flexible printed wiring board material 12). ).

  As shown in FIG. 9, the exposure area 16 by the exposure head 14 is configured in a rectangular shape having a short side in the feed direction (main scanning direction), for example. In this case, a strip-shaped exposed region 18 is formed on the flexible printed wiring board material 12 in accordance with the scanning exposure moving operation.

  As shown in FIG. 7, the exposure head 14 includes a spatial light modulator (two-dimensional light modulator) that modulates each incident light beam for each pixel in accordance with image data corresponding to a predetermined exposure area on a plane. ) Includes a digital micromirror device (DMD) 20. The DMD 20 which is a two-dimensional optical modulator is driven and controlled by a control unit (control means) 22 having data processing means and mirror drive control means.

  The data processing unit of the control unit 22 controls driving of the micromirrors in the region to be controlled by the DMD 20 to the exposure head 14 based on the input image data (control of the angle of each micromirror reflecting surface). Control signal is generated.

  Connected to the light incident side of the DMD 20 in the exposure head 14 are bundle optical fibers 28 each drawn from a light source unit 24 that is an illumination device that emits multi-beams as laser light.

  The light source unit 24 is provided with a plurality of multiplexing modules 26 that combine laser beams such as ultraviolet rays emitted from a plurality of semiconductor laser chips and input them to an optical fiber. The optical fiber extending from each multiplexing module 26 is a multiplexing optical fiber that propagates the combined laser beam, and a plurality of optical fibers are bundled into one to form a bundle-shaped optical fiber (fiber bundle) 28. The laser beam is configured to improve the intensity of the emitted laser beam.

  On the light incident side of the DMD 20 in the exposure head 14, there is provided a mirror 32 that reflects the laser light emitted from the connection end of the bundle optical fiber 28 toward the DMD 20 through an optical lens having a rod lens or the like. Arrange the illumination optical system.

  As shown in FIG. 8, the DMD 20 is entirely monolithic as a mirror device in which a plurality of micromirrors 36 (for example, 600 × 800) constituting a pixel (pixel) are arranged in a lattice pattern. (Integrated type).

  A material having high reflectivity such as aluminum is deposited on the surface of the micromirror 36 disposed at the top of each pixel. In addition, a column 34 projects from the center of the lower surface of each micromirror 36.

  This DMD 20 is provided with a pillar 34 projecting from a micromirror 36 on a hinge 40 provided on a silicon gate CMOS SRAM cell 38 which is manufactured in a normal semiconductor memory manufacturing line corresponding to each pixel. And the micromirror 36 is mounted so as to be tiltable by ± a degrees (± 10 degrees) in the diagonal direction about the hinge 40 as an axis.

  Further, in this DMD 20, static electricity due to charges accumulated on one side or the other side of each of the mirror address electrodes 42 respectively formed at both ends in the diagonal direction in which the micromirrors 36 on the SRAM cell 38 are inclined. Utilizing force, the micromirror 36 is configured to be driven and controlled to be in a state tilted to + a degrees when the micromirror 36 is in an on state or in a state tilted to -a degrees when the micromirror 36 is in an off state.

  In the DMD 20 configured as described above, when a digital signal is written to the SRAM cell 38, the micromirrors 36 in the respective pixels of the DMD 20 correspond to the substrate side on which the DMD 20 is disposed with the diagonal line as the center in accordance with the image signal. Thus, the light is incident on the DMD 20 and is reflected in the tilt direction of each micromirror 36.

  The light reflected by the on-state micromirror 36 is modulated into an exposure state and is incident on a projection optical system (see FIG. 7) provided on the light exit side of the DMD 20. The light reflected by the micromirror 36 in the off state is modulated into a non-exposure state and enters a light absorber (not shown).

  Next, a projection optical system (imaging optical system) provided on the light reflection side of the DMD 20 in the exposure head 14 will be described. As shown in FIG. 7, the projection optical system (imaging optical system) provided on the light reflection side of the DMD 20 in the exposure head 14 forms an image on the flexible printed wiring board material 12 on the exposure surface on the light reflection side of the DMD 20. Therefore, in order from the DMD 20 side toward the flexible printed wiring board material 12, the first imaging optical lens systems 44, 46, the microlens array 48 as an intermediate imaging unit, and the second imaging optical lens Optical members for exposure with the systems 52 and 54 and the prism pair 56 for autofocus are arranged. Although not shown in the drawing, the exposure head 14 may be configured by disposing aperture arrays at positions near the front and rear of the microlens array 48 on the optical path.

  In the exposure head 14 configured as described above, the second imaging optical lens system 52 passes through the first imaging optical lens systems 44 and 46 and the microlens array 48 provided on the light reflection side of the DMD 20. , 54 is focused and imaged on the flexible printed wiring board material 12 placed on the outer peripheral surface of the exposure head 14 by the autofocus function of the prism pair 56 and exposed. Note that each of the first imaging optical lens systems 44 and 46 and the second imaging optical lens systems 52 and 54 in the projection optical system is shown as one lens in FIG. A lens (for example, a convex lens and a concave lens) may be combined.

  Next, the exposure head 14 can perform high-precision exposure processing on the surface (three-dimensional exposed surface) of the flexible printed wiring board material 12 that is curved along the outer peripheral surface of the drum 10 and curved in an arc shape. In order to achieve this, the focal point is placed over the entire exposure area exposed at one time by the exposure head 14 arranged on the optical path of the exposure light beam from the DMD 20 installed in the exposure head 14 to the flexible printed wiring board material 12. The focal length adjusting means for forming an image together will be described.

  This focal length adjusting means focuses each laser beam reflected by each micromirror 36 of the DMD 20 on the curved surface of the flexible printed circuit board material 12 that is wound around the drum 10 and curved in an arc shape. It is constituted by an optical member of an optical system related to the exposure head 14 that changes the focal length so as to be imaged.

  For example, as shown in FIGS. 1, 2 to 4, and 7, the focal length adjusting unit can be configured by a microlens array 48 that is an intermediate imaging unit used in the projection optical system of the exposure head 14. . The microlens array 48 is formed by integrally forming a plurality of microlenses 47 that correspond one-to-one to each micromirror 36 of the DMD 20 that reflects laser light emitted from the light source unit 24 through the optical fiber 28. Each microlens 47 is arranged on the optical axis of each laser beam transmitted through the first imaging optical lens systems 44 and 46, respectively.

  The microlens array 48 that constitutes the focal length adjusting means is formed so that each laser beam passing through each microlens 47 is focused on the curved surface of the flexible printed wiring board material 12 that is curved in an arc shape. The focal length of each microlens 47 is set and configured.

  In the microlens array 48 constituting the focal length adjusting means corresponding to the surface of the flexible printed wiring board material 12 having a convex arcuate curved surface wound around the cylindrical drum 10, the microlens array 48 is a drum. 10 when arranged parallel to the tangent line of the outer peripheral surface (tangential line in the direction orthogonal to the central axis of the drum 10) than the focal length of the microlens 47 located in the center with respect to the conveyance direction of the microlens array The field curvature is corrected so that the focal lengths of the microlenses 47 positioned on both end sides with respect to the conveyance direction of the microlens array 48 are longer.

In the case of such a configuration, as shown in FIGS. 3 and 4, the focal length of each microlens 47 can be calculated and set using the formula L = M ² × d. Here, L is a difference in focal length on the exposure surface, M is a magnification of the exposure head 14, and d is a difference in focal position of each microlens 47 with respect to the microlens 47 having the shortest focal length.

  In this microlens array 48, the focal position difference of each microlens 47 is determined so that the focal length difference L on the exposure surface of each microlens 47 coincides with the arcuate curved surface of the flexible printed wiring board material 12. .

  That is, in the microlens array 48, the microlenses 47 are arranged in a plane, and the focal length of each microlens 47 is configured to coincide with the arcuate curved surface of the flexible printed wiring board material 12.

  Although the exposure apparatus is not shown in the drawing, when it is configured as a so-called inner drum type exposure apparatus that exposes a flexible printed wiring board material cut to a predetermined size along the inside of the cylindrical surface, in the microlens array 48 Contrary to the above, the focal length of each microlens 47 is opposite to the focal length of the microlens 47 located in the center, and the focal points of the microlenses 47 located on both ends of the microlens array 48 in the transport direction. The distance is configured to be shorter.

  Next, another configuration example of the microlens array 48 constituting the focal length adjusting means will be described with reference to FIG. In the microlens array 48 shown in FIG. 5, each microlens 47 is formed with the same curvature (formed with the same focal length), and each microlens 47 is formed with the flexible printed wiring board material 12. It is configured to be positioned on a parallel arcuate curved surface having a focal length from the arcuate curved surface.

  With this configuration, each microlens 47 corresponds to a position where the length of the focal length is set from the arcuate curved surface of the flexible printed wiring board material 12, so that each laser beam passing through the microlens 47 is Each image is focused on the curved surface of the flexible printed wiring board material 12 curved in an arc shape. Therefore, in the case of such a configuration, the curved surface of the flexible printed wiring board material 12 in which the projection image of the DMD 20 is three-dimensionally developed by focusing all the laser beams on the entire exposure area by the exposure head 14. The exposure process can be performed with high accuracy.

  Next, a configuration example in which the focal length adjusting means used in the exposure head 14 is constituted by a concave lens placed in the middle of the imaging optical system will be described with reference to FIG.

  This focal length adjusting means forms an image of the exposure light beam projected from the projection optical system of the exposure head 14 on the two-dimensional exposure region (planar exposure region) of the flexible printed wiring board material 12. The cylindrical lens 100 is changed so as to form an image on a three-dimensional exposure region that is an arcuate curved surface.

  The cylindrical lens 100 is arranged in parallel with the central axis of the drum 10, and corresponds to the full width of the curved surface of the exposure surface of the flexible printed wiring board material 12 so arranged on the outer peripheral surface of the drum 10. The concave lens is formed parallel to the curved surface of the exposure surface.

  The cylindrical lens 100 forms an image of a light beam for exposure projected from the exposure head 14 on a two-dimensional exposure region (planar exposure region) on the plane E shown in FIG. There is an effect that an image is formed on the curved surface (three-dimensional exposure region) of the exposure surface of the substrate material 12.

  The cylindrical lens 100 projects into a three-dimensional exposure region on the flexible printed wiring board material 12 when forming an image on the curved surface (three-dimensional exposure area) of the exposure surface of the flexible printed wiring board material 12. When the exposure laser beams spread outward on the upstream side and the downstream side in the main scanning direction (conveying direction) as indicated by the solid line in FIG. 6, although not shown, a correction lens is used. Thus, the optical path of each exposure laser beam may be corrected as illustrated by a broken line in FIG.

  Further, since the exposure surface of the flexible printed wiring board material 12 is an upwardly convex arcuate curved surface, the optical path of each exposure laser beam is not spread on the plane E as illustrated by a broken line in FIG. Even if corrected and exposed, distortion of the image in which the image exposed when the flexible printed wiring board material 12 is returned to the flat state spreads outward on the upstream side and the downstream side in the main scanning direction (conveyance direction). Produce. In the case of correcting this, for example, an image may be formed with higher accuracy by correcting using another correction lens.

  Next, the operation and operation of the exposure apparatus according to the present embodiment configured as described above will be described.

  In this exposure apparatus, the flexible printed wiring board material 12 to be subjected to the exposure process passes from the unexposed recording medium supply unit through the exposure processing unit 11 via the dancer roller mechanism as the tension setting unit, and is the tension setting unit. It is set on the conveyance path to the exposed recording medium collection unit via the dancer roller mechanism.

  Next, in this exposure apparatus, while rotating the drum 10 to feed the flexible printed wiring board material 12, the camera unit 86 photographs the mark on the flexible printed wiring board material 12 at a predetermined interval to correct the image recording position. Processing including (exposure start time correction) is performed.

  Next, in this exposure apparatus, the flexible printed wiring board material 12 is exposed by each exposure head 14. In this exposure process, each exposure head 14 irradiates the DMD 20 with laser light based on the exposure data deformed by the control unit (not shown), and is reflected when the micromirror of the DMD 20 is turned on. The laser beam thus formed is imaged on the flexible printed wiring board material 12 through an optical path set by the optical system.

  In this exposure apparatus, the flexible printed wiring board material 12 wound around the drum 10 is drawn by laser exposure while being continuously conveyed in the main scanning direction in synchronization with the rotation operation of the drum 10. Therefore, this exposure apparatus can always increase the productivity because the exposure process can be continuously performed as compared with the exposure apparatus that performs the alignment adjustment process on the recording medium in the forward path and the exposure process on the return path.

  In this embodiment, a DMD 20 is used as a spatial modulation element used for the exposure head 14 of the exposure head unit 82 configured as a laser exposure apparatus, and a dot pattern is generated by turning on / off at a constant lighting time. Alternatively, a dot pattern may be generated by performing pulse width modulation by on-time ratio (duty) control. Alternatively, the dot pattern may be generated according to the number of times of lighting, with one lighting time being extremely short.

  Further, in the present embodiment, the exposure head 14 including the DMD 20 as the spatial light modulation element has been described. However, in addition to such a reflective spatial light modulation element, for example, a micro electro mechanical systems (MEMS) type space. Light modulation element (SLM), transmissive spatial light modulation element (LCD), optical element (PLZT element) that modulates transmitted light by electro-optic effect, and liquid crystal shutter array of liquid crystal light shutter (FLC) A spatial light modulation element other than the MEMS type can be used instead of the DMD. Further, a plurality of grating light valves (GLVs) arranged in two dimensions can be used. In the configuration using these reflective spatial light modulator (GLV) and transmissive spatial light modulator (LCD), a lamp or the like can be used as a light source in addition to the laser described above.

  As a light source in this embodiment, a fiber array light source provided with a plurality of combined laser light sources, one optical fiber that emits laser light incident from a single semiconductor laser having one light emitting point A fiber array light source in which the provided fiber light sources are arrayed, a light source in which a plurality of light emitting points are arranged two-dimensionally (for example, an LD array, an organic EL array, etc.), and the like can be applied.

  The exposure apparatus can use either a photon mode photosensitive material in which information is directly recorded by exposure or a heat mode photosensitive material in which information is recorded by heat generated by exposure. When using a photon mode photosensitive material, a GaN-based semiconductor laser, a wavelength conversion solid-state laser, or the like is used for the laser device. When using a heat mode photosensitive material, an AlGaAs-based semiconductor laser (infrared laser), A solid state laser is used.

  Note that the exposure apparatus of the present invention may be configured as an apparatus that performs drawing processing on a display substrate in addition to drawing processing on the flexible printed wiring board material 12 as a long strip-like flexible recording medium.

  Further, the present invention is not limited to this, and it is needless to say that various other configurations can be taken without departing from the gist of the present invention.

It is a schematic block diagram which shows the principal part of the exposure apparatus which concerns on embodiment of this invention. It is a perspective view which illustrates the micro lens array which comprises the focal distance adjustment means used for the exposure apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the state exposed on the circular curved surface of a flexible printed wiring board material with the exposure head of the exposure apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the conditions for setting the focal distance of each micro lens in the micro lens array which comprises the focal distance adjustment means used for the exposure apparatus which concerns on embodiment of this invention. It is a principal part enlarged explanatory view which illustrates other structures of the micro lens array which comprises the focal distance adjustment means used for the exposure apparatus which concerns on embodiment of this invention. It is a principal part expansion explanatory drawing which shows the structure which exposes with an exposure head using a cylindrical lens as a focal distance adjustment means used for the exposure apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the exposure head part used for the exposure apparatus which concerns on embodiment of this invention. It is a perspective view which shows schematic structure of DMD used for the exposure head of the exposure apparatus which concerns on embodiment of this invention. It is a perspective view of the principal part which shows the state which is performing the exposure process with the exposure head of the exposure apparatus which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Drum 11 Exposure processing part 12 Flexible printed wiring board material 14 Exposure head 16 Exposure area 36 Micro mirror 47 Micro lens 48 Micro lens array 60 Supply reel 68 Dancer roller 70 Take-up reel 82 Exposure head unit 100 Cylindrical lens

Claims (6)

A drum that is rotationally driven with the flexible recording medium along the surface;
An exposure head including a two-dimensional light modulator that modulates an incident light beam for each pixel in accordance with image data corresponding to a predetermined exposure area on a plane;
Focal length adjustment means for focusing and imaging an exposure light beam projected from the exposure head over the entire three-dimensional exposure area on the arcuate curved surface of the flexible recording medium along the drum. When,
An exposure apparatus comprising:   2. The exposure apparatus according to claim 1, wherein the two-dimensional light modulator is constituted by a digital micromirror device (DMD).   The said focal distance adjustment means is comprised with the micro lens array which provided the micro lens in which each focus position corresponds to the circular arc curved surface of the said flexible recording medium, The Claim 1 or Claim 2 characterized by the above-mentioned. Exposure device.   The microlens array is configured so that all the microlenses are arranged in a plane, and the focal length of each microlens coincides with an arcuate curved surface of the flexible recording medium. Item 4. The exposure apparatus according to Item 3.   The microlens array is configured so that the focal lengths of all the microlenses are made constant, and the microlens array is positioned on a parallel arcuate curved surface having a focal length from the arcuate curved surface of the flexible recording medium. The exposure apparatus according to claim 3.   In the focal length adjusting means, the light beam for exposure projected from the projection optical system of the exposure head forms an image on a two-dimensional exposure area on the circular curved surface of the flexible recording medium 3. The exposure apparatus according to claim 1, wherein the exposure apparatus includes a cylindrical lens that is changed so as to form an image in a two-dimensional exposure region.

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