Abstract:
In order that an exposure apparatus for producing exposed structures in a photosensitive layer arranged on an object, comprising an object carrier and an exposure device, wherein the object carrier and the exposure device can be moved relative to one another in an advance direction and wherein exposure spots can be produced on the photosensitive layer in a position-controlled manner by means of the exposure device transversely with respect to the advance direction, is improved in such a way that a highest possible exposure power is available, i.e. a largest possible number of exposure spots can be produced per unit time, it is proposed that the exposure device has at least one exposure unit with a series of radiation exit regions which are arranged successively in a series direction and from which exposure beams emerge, by means of each of which, passed through an imaging optical system, an exposure spot can be produced on the photosensitive layer and each of which can be deflected by a deflection unit in a deflection direction running transversely with respect to the series direction, such that each exposure beam can produce exposure spots that at least partly overlap one another in a multiplicity of successive exposure spot positions in the deflection direction.

Description:
[0001]    This application is a continuation of International application No. PCT/EP2007/010648 filed on Dec. 7, 2007. 
         [0002]    This patent application claims the benefit of International application No. PCT/EP2007/010648 of Dec. 7, 2007 and German application No. 10 2006 059 818.0 of Dec. 11, 2006, the teachings and disclosure of which are hereby incorporated in their entirety by reference thereto. 
     
    
     BACKGROUND OF THE INVENTION 
       [0003]    The invention relates to an exposure apparatus for producing exposed structures in a photosensitive layer disposed on an object, comprising an object carrier accommodating the object and an exposure device, the object carrier and the exposure device being movable in relation to one another in a direction of advance and it being possible for exposure spots to be produced by the exposure device on the photosensitive layer in a position-controlled manner, transversely with respect to the direction of advance. 
         [0004]    Such exposure apparatuses are known from the prior art, the object of these exposure apparatuses being to expose the photosensitive layer with the highest possible precision. 
         [0005]    On the basis of these known solutions, it is an object of the present invention to improve an exposure apparatus of the generic type in such a way that an exposure power that is as high as possible is provided, that is to say as large a number of exposure spots as possible can be produced per unit of time. 
       SUMMARY OF THE INVENTION 
       [0006]    This object is achieved according to the invention in the case of an exposure apparatus of the type described at the beginning by the exposure device having at least one exposure unit with a series of radiation exit regions which are disposed successively in a series direction and from which exposure beams emerge, with each of which beams, directed through an imaging optical system, an exposure spot can be produced on the photosensitive layer and each of which beams can be deflected by a deflection unit in a direction of deflection running transversely with respect to the series direction such that each exposure beam can be used to produce exposure spots that at least partly overlap one another in a multiplicity of successive exposure spot positions in the direction of deflection. 
         [0007]    The advantage of the solution according to the invention can be seen in that it allows such an exposure apparatus to simultaneously produce a high number of exposure spots, the position of which can be defined on the one hand by the deflection unit and on the other hand by the movement in the direction of advance. 
         [0008]    In the case of this solution, it is particularly advantageous if the direction of deflection runs at an angle with respect to the direction of advance, so that there is the possibility of simultaneously exposing exposure spots lying next to one another transversely with respect to the direction of advance by the various exposure beams of the at least one exposure unit, in spite of the direction of deflection running transversely with respect to the series direction. 
         [0009]    It is particularly advantageous, furthermore, if the exposure spots of successive exposure beams of the at least one exposure unit are movable along directions of deflection that are parallel to one another, since easy simultaneous positioning of the exposure spots that can be produced by the various exposure beams can be realized in this way. 
         [0010]    Furthermore, it is advantageous if the exposure beams of the at least one exposure unit can be deflected simultaneously and to the same extent by the deflection unit, so that, as a result, the positioning of the exposure spots produced by these exposure beams is made easier, since the relative position of the exposure spots is fixed in a defined manner for a control unit. 
         [0011]    In order also to influence the photochemical processes in the photosensitive layer as far as possible to the same extent and obtain photochemical conversion processes that are as identical as possible in the case of all the exposure beams, it is advantageously provided that the exposure beams of an exposure unit are aligned substantially parallel to one another when they impinge on the photosensitive layer, so that the alignment of the exposure beams cannot cause different effects. 
         [0012]    Furthermore, it is advantageous if the movement of each exposure spot produced by an exposure beam in the respective direction of deflection takes place over a path of deflection which is approximately the same size for each exposure beam of the exposure unit. This allows the positioning of the exposure spots to be fixed and carried out by means of the control unit in a simple way. 
         [0013]    In order to achieve the effect that the exposure spots produced by different exposure beams can be positioned in such a way that contiguous structures, in particular with a component in a transverse direction, can be produced with the exposure spots provided by different exposure beams, it is preferably provided that the exposure spot of the final exposure spot position of one path of deflection and the exposure spot of the first exposure spot position of the next path of deflection following in the series direction are disposed in such a way with respect to a straight reference line running parallel to the direction of advance that the straight reference line intersects the exposure spots produced in these exposure spot positions. 
         [0014]    It is ensured by this provision that the exposure spots of the final exposure spot position of one exposure beam and of the first exposure spot position of the next exposure beam following in the series direction are disposed in relation to one another transversely with respect to the direction of advance such that, with suitable displacement in the direction of advance, they overlap at least slightly. 
         [0015]    It is particularly advantageous if a straight reference line running parallel to the direction of advance through the final exposure spot position of one path of deflection intersects the exposure spot of a first exposure spot position of a next-following path of deflection. 
         [0016]    If it is assumed that a center point of the respective exposure spot is to be taken as the exposure spot position, it is ensured by this provision that, with suitable displacement in the direction of advance, the two exposure spots overlap by approximately at least half, a provision which is advantageous whenever a contiguous structure is to be produced in the photosensitive layer by way of the exposure spots of different paths of deflection. 
         [0017]    It is still more advantageous if the first exposure spot position of the next-following path of deflection is at a distance from the straight reference line that corresponds at most to half the diameter of the exposure spot, so that the overlapping of the two exposure spots is still greater, that is to say at least half the diameter, but usually more than that. 
         [0018]    In order to be able within the scope of the solution according to the invention to produce as many exposure spots as possible simultaneously, it is preferably provided that a plurality of exposure units are provided, the exposure units being disposed at a distance from one another in the direction of deflection. 
         [0019]    Furthermore, with such a plurality of exposure units, it is provided that the deflecting directions of the plurality of exposure units run parallel to one another, so that as a result the establishment of the individual exposure spot positions for the control unit can be carried out more easily and efficiently. 
         [0020]    The plurality of exposure units could be disposed in relation to one another in such a way that the series directions of successive exposure units run transversely with respect to one another. 
         [0021]    Furthermore, in the case of an exemplary embodiment, it is provided that the series direction of the plurality of exposure units run substantially parallel to one another, so that ultimately the individual series in the plurality of exposure units are also aligned substantially parallel to one another. 
         [0022]    In order even in the case of a plurality of exposure units to be able to produce contiguous structures with the exposure spots that can be produced by them, it is provided that the plurality of exposure units are disposed with respect to a straight reference line running parallel to the direction of advance in such a way that the straight reference line intersects the exposure spot of the final exposure spot position of the final deflecting path of one exposure unit and the exposure spot of the first exposure spot position of the first exposure spots of the next exposure unit following in the direction of deflection or in the transverse direction. Also as a result, at least a slight overlapping of the two exposure spots is ensured, in order to be able to produce, with the exposure spots of different exposure units, contiguous structures which run with at least one component in the transverse direction. 
         [0023]    However, the overlapping is even better if the straight reference line running through the final exposure spot position of a final deflecting path of one exposure unit intersects the exposure spot of the first exposure spot position of a first deflecting path of a next following exposure unit in the direction of deflection or transverse direction, so that, on the basis of the fact that the exposure spot position is defined by the center point of the respective exposure spot, the two exposure spots overlap by at least approximately half. 
         [0024]    A further provision that is suitable for the overlapping provides that the first exposure spot position is at a distance from the straight reference line that corresponds at most to half the diameter of the exposure spot of the first exposure spot position. 
         [0025]    With regard to the deflection units, no further details have been specified so far. 
         [0026]    Within the scope of the solution according to the invention, it would in principle be conceivable to provide each exposure beam with its own dedicated deflection unit, in which case the deflection units could also operate differently. 
         [0027]    As a solution that is advantageous for reasons concerning the production of an exposure apparatus of this kind, it is provided that the deflection unit has a reflective surface region for each of the exposure beams. 
         [0028]    In this case, the individual reflective surface regions may still be movable independently of one another. For reasons of structural unity, however, it is advantageous if the reflective surface regions of an exposure unit are jointly movable. 
         [0029]    The reflective surface regions can be realized particularly advantageously if the reflective surface regions are partial regions of a common reflective surface. 
         [0030]    In order to achieve a deflection with these reflective surface regions, it is advantageous if the reflective surface regions can be tilted in relation to the direction of impingement of the exposure beams on these regions, since such a tilting movement of the reflective surface regions can be mechanically realized in a simple way. 
         [0031]    In principle, the reflective surface regions may be curved, in order, for example, also to simultaneously carry out focusing with them, but a solution in which the reflective surface regions are planar surface regions is structurally particularly simple. 
         [0032]    It is structurally particularly advantageous if all the reflective surface regions lie in a common plane, which makes it easier to carry out the tilting movement. 
         [0033]    In the case of this solution, it is advantageous in particular to dispose the reflective surface regions in such a way that the reflective surface regions on which the exposure beams of an exposure unit impinge lie in the same plane. 
         [0034]    In order to achieve a deflection of the respective exposure beam that is as efficient as possible, it is provided that the exposure unit has a plurality of reflective surface regions for each exposure beam. 
         [0035]    In this case, it is particularly advantageous if the deflection unit has for each exposure beam a plurality of reflective surface regions that are used one after the other for deflecting the exposure beam, so that each exposure beam is deflected by a multiplicity of reflective surface regions that are used one after the other. 
         [0036]    Such a number of reflective surface regions can be realized in a structurally simple manner if the plurality of reflective surface regions are formed by circumferential sides of a rotatably disposed reflective body. 
         [0037]    The reflective body could in this case still be able to tilt about an axis in an oscillating manner. 
         [0038]    However, to achieve a deflecting speed that is as high as possible, it is particularly advantageous if the reflective body is disposed such that it rotates about an axis. 
         [0039]    In this case, the reflective surface regions are suitably disposed around the axis at the same radial distance, the reflective surface regions preferably extending parallel to the axis. 
         [0040]    In this case, the reflective surface regions could also have curved reflective surfaces, which, however, run parallel to the axis in spite of the curvature. 
         [0041]    In order to be able to assign the position of the reflective surfaces in a defined manner to the respectively corresponding exposure spot positions, it is preferably provided that the reflective body rotates about its axis at a constant speed. 
         [0042]    Within the scope of the solution according to the invention, no further details have been specified as to how the exposure beams emerging from the radiation exit regions are to be produced. For example, the radiation exit regions could actually be exit regions of radiation sources, for example laser diodes. 
         [0043]    It is still more advantageous, however, if the radiation exit regions are ends of optical fibers. 
         [0044]    This provides the possibility of disposing the radiation regions and the radiation sources separately from one another. 
         [0045]    In order, however, to be able to control the intensity specifically in each individual radiation region, it is provided that each optical fiber has its own dedicated radiation source, so that the intensity emerging from the radiation exit regions can be controlled by the intensity control of this radiation source, whether by intensity control of the radiation source itself or of a downstream intensity control element. 
         [0046]    Likewise preferably provided in this case as a radiation source is a laser, which for reasons of simple construction is preferably a semiconductor laser. 
         [0047]    It is particularly advantageous in this case if the radiation sources are disposed in a radiation generating unit located separately from the exposure device, since there is then the possibility of efficiently cooling the radiation sources and, in particular, there is no risk of thermal problems with regard to the accuracy of the exposure spot positions that can be produced by the exposure device being caused by the heat generated by the radiation sources. 
         [0048]    Further features and advantages of the solution according to the invention are the subject of the following description and the pictorial representation of an exemplary embodiment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0049]      FIG. 1  shows a schematic perspective representation of an exemplary embodiment of an exposure apparatus according to the invention; 
           [0050]      FIG. 2  shows an enlarged representation of a detail of an object with a photosensitive layer and structures possibly to be produced therein, disposed on an object carrier; 
           [0051]      FIG. 3  shows a schematic representation of a detail of a partial region of an exposure region in which exposure spots can be produced; 
           [0052]      FIG. 4  shows a schematic representation of a detail of two exposure units; 
           [0053]      FIG. 5  shows a plan view in the direction of an arrow A of one of the exposure units; 
           [0054]      FIG. 6  shows an enlarged representation of a detail of exposure spot positions and exposure spots that can be produced by two exposure beams; 
           [0055]      FIG. 7  shows a schematic enlarged representation of the movement of an exposure beam in the direction of deflection and 
           [0056]      FIG. 8  shows a schematic enlarged representation, in a section along line  8 - 8  in  FIG. 1 , of exposure units of the exposure device that are disposed next to one another. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0057]    An exemplary embodiment of an exposure device represented in  FIG. 1  comprises a machine base, which is designated as a whole by  10  and has a guide  12 , on which an object carrier  14  is on the one hand movably guided in the direction of a direction of advance  16  and on the other hand is movable by drives, for example linear drives, preferably in a positionally precise manner. 
         [0058]    The guide  12  is in this case disposed, for example, on a side of the machine base  10  that is facing away from a standing surface  18  and guides the object carrier  14  in such a way that, as represented in  FIG. 2 , an object  22  can be placed and fixed on its upper side  20 , that faces away from the machine base  10 , which object is provided on its side that is once again facing away from the object carrier  14  with a photosensitive layer  24 , in which structures  26  can be produced by suitable exposure, as a result of optical transformation of the material of the photosensitive layer  24 . 
         [0059]    Such structures  26  serve, for example, for selectively masking individual regions of a layer  28 , for example a copper layer  28 , of the object  22 , in order then, for example in the process of an etching operation, to remove the layer  28  at the locations at which it is not masked by the structures  26 , so that the layer  28  only remains in the regions in which it is masked by the structures  26 . 
         [0060]    Producing the structures  26  represented in  FIG. 2  by optical transformation of the photosensitive layer  24  takes place by an exposure device, which is designated as a whole by  30  and is disposed on a bridge  32 , which is supported on both sides of the guide  12  on the machine base  10  and otherwise extends above the guide  12 . 
         [0061]    In the case of the exemplary embodiment represented, it is possible with the exposure device  30  according to the invention, by a single movement of the object carrier  14  with the object  22  with the photosensitive layer  24 , to produce, by exposure, within a structure region  34 , all the structures  26  intended in this structure region  34  in the course of a single movement of the photosensitive layer  24  in the direction of advance, the exposure device  30  being capable in the course of the single movement of the photosensitive layer  24  in the direction of advance  16  to expose the structure region  34  both in its longitudinal direction  36  and in its transverse direction  38  in one go, in order to produce all the structures  26  intended and required within the structure region  34  without requiring further movements of the object carrier  14  in the direction of advance  16 . 
         [0062]    However, in the case of a modification of the first exemplary embodiment, it is conceivable to move the object carrier  14  once in a direction of the direction of advance  16  and another time in the opposite direction, so that, starting from a starting position represented in  FIG. 1 , a back and forth movement of the object carrier  14  leads to the desired comprehensive exposure in the structure region  34 , so that it would be conceivable, for example, to expose half the structure region  34 , seen in the transverse direction  38 , in the course of a movement in a direction of the direction of advance  16  and, if appropriate, the other half in the opposite direction. 
         [0063]    In order to be able to produce all the required structures  26  within this structure region  34 , it is possible to produce within an exposure region  40 , represented in  FIG. 1  and partly in  FIG. 3 , individual exposure spots  42  which are disposed within the exposure region  40  in such a way that the sum of all the exposure spots  42  present in the exposure region  40  comprises all those exposure spots  42  that are required to produce, in the transverse direction  38 , a linear structure that extends over the entire extent of the structure region  34  in the transverse direction  38  and is uninterruptedly continuous in the transverse direction  38 , for which purpose the exposure spots  42  are to be disposed in such a way that they overlap exposure spots  42  successively following one another in the transverse direction  38 . 
         [0064]    That is to say in other words that the exposure spots  42  that can be produced within the exposure region  40  are of such a size and are disposed in such a way that, taking into account the movement of the object  22  in the direction of advance  16 , they can be used to produce all possible structures  26  over the whole area in the entire structure region  34  of the photosensitive layer  24  in the process of the resolution that is caused by the areal extent of the exposure spots  42  in the longitudinal direction  36  and the transverse direction  38 . 
         [0065]    In order to be able to produce the exposure spots  42  in the required number and position within the exposure region  40 , provided in the exposure device  30 , as represented in  FIG. 4 , are a number of exposure units  50 , each of which has, as represented in  FIG. 5 , a series of radiation exit regions  54 , which are disposed successively in a series direction  53  and at a distance from one another and from which exposure beams  56  respectively emerge, which beams are transformed by optical systems  58  into collimated exposure beams  60 , the collimated exposure beams  60  then being deflected, as represented in  FIGS. 4 and 5 , by a deflection unit  62 , transversely with respect to their direction of propagation, and thereby impinging on a deflection unit  64 , which is represented in  FIG. 4  and, as represented in  FIG. 4 , deflects the collimated exposure beams  60  into exposure beams  66  moving in a direction of deflection  68  transversely with respect to a direction  53 . 
         [0066]    The deflection unit  64  comprises a reflective body  70 , which is disposed symmetrically with respect to an axis  72  and has reflective surfaces  74 , which extend parallel to the axis  72  and are preferably disposed on the circumferential surface of the reflective body  70 . 
         [0067]    The reflective surfaces  74  preferably substantially border one another in the circumferential direction  76  and extend over the same length or width in their longitudinal direction  82  and in their transverse direction  84 , so that all the reflective surfaces  74  have the same extent. 
         [0068]    In addition, all the reflective surfaces  74  are planar surfaces, so that, in the simplest case, the reflective body  70  has a cross-sectional area which is a regular polygon, the number of reflective surfaces  74  being, for example, greater than 4 and less than 40. 
         [0069]    A preferred embodiment provides that the number of reflective surfaces  74  is greater than 12 and less than 30. 
         [0070]    Each of the reflective surfaces  74  reflects with in each case one reflective surface region  78  in each case one collimated exposure beam  60 , deflected by the deflection unit  62 , in a manner corresponding to the respective rotational position of the reflective body  70 , in such a way that, as represented in  FIGS. 6 and 7 , in a first position of the reflective surface  74 , the moving exposure beam  66   1  produces an exposure spot  42   11 , in a first exposure spot position  90   11 , which can then move further in the direction of the deflecting direction  68  over a path of deflection AS, to a final exposure spot position  90   1N , which corresponds to the position of the respective reflective surface  74  in which the exposure beam  60   1  still impinges on it and consequently still serves for producing the exposure spot  42   1N  that is associated with the final exposure spot position  90   1N . 
         [0071]    Further turning of the reflective body  70  in the direction of rotation  77  then has the effect that the exposure beam  60   1  impinges on the next reflective surface  74 , which then once again reflects the exposure beam  60   1  into the moving exposure beam  66   1  in such a way that the latter in turn produces the exposure spot  42   11 , in the first exposure spot position  90   11 . 
         [0072]    Consequently, the constant rotation of the reflective body  70  about the axis  72  leads to a constant travelling movement of the exposure spots  42   1  from the first exposure spot position  90   11  to the final exposure spot position  90   1N  over the paths of deflection AS on the photosensitive layer  24 . 
         [0073]    This provides the possibility of carrying out an exposure of the photosensitive layer  24  in the region of the path of deflection AS along the direction of deflection  68  by the exposure spots  42   1  in exposure spot positions  90   1  that can be chosen in a defined manner, to be precise when the respective exposure spot  42  is in the respective exposure spot position  90   1 , it only being possible in this position that an exposure with adequate intensity takes place on the photosensitive layer  24 , by activating the respective exposure beam  66   1 , that is to say for example switching on the radiation source associated with the radiation exit  54   1 , an exposure by which a photochemical conversion in the photosensitive layer can be achieved in the region of this exposure spot  42   1 . 
         [0074]    If no exposure of the photosensitive layer  24  is intended in the other exposure spot positions  90   1  within the path of deflection AS, the radiation source associated with the respective radiation exit  54   1  is not switched on when these exposure spot positions  90   1  are passed through, or said source is operated with an intensity that cannot lead to photochemical conversion of the photosensitive layer  24  in the region of the respective exposure spot  42   1 . 
         [0075]    For this purpose, as represented in  FIG. 8 , the reflective bodies  70  of the deflection units  64  are rotatably mounted about the axis  72  on both sides by bearing devices  92  and  94  and are also driven in rotation at a constant speed by a drive  96 , each drive  96  also having an associated sensor  98 , which is capable of sensing the rotational position of the reflective body  70 , and consequently in particular the position of the reflective surfaces  74 , for a control unit that is designated as a whole by  100  and controls the exposure. 
         [0076]    For focusing the moving exposure beams  66  onto the photosensitive layer  24 , and consequently setting the extent of the exposure spots  42  produced by the respective exposure beams  66 , also provided between the deflection unit  64  and the photosensitive layer  24  is an optical unit  102 , which has for each of the exposure beams  66  a dedicated optical imaging system  104 , for example in the form of a lens, through which the respective moving exposure beam  66  passes and the respective exposure spot  42  is thereby focused onto the photosensitive layer  24  with a defined size of the exposure spot  42  and a defined intensity distribution in the exposure spot  42 . 
         [0077]    In particular, advantageous imaging properties of the optical imaging system  104  are obtained if the average distance between the active reflective surface region  78  of the reflective surface  74  and the optical imaging system  104  corresponds approximately to the focal length f of the optical imaging system  104 , so that the image ratios for the moving exposure beam are substantially identical, and consequently also the exposure spots  42  are of substantially the same size and have substantially the same intensity distribution ( FIG. 7 ). 
         [0078]    Furthermore, it is preferably provided that the distance between the optical imaging system  104  and the photosensitive layer  24  to be exposed corresponds approximately to the focal length f of the optical imaging system  104  ( FIG. 7 ), in order to obtain optimum focusing of the respective exposure beam  66  in the exposure spot  42  on the photosensitive layer  24 . 
         [0079]    With regard to the production of the exposure beams  56 , no further details have been specified so far. 
         [0080]    A radiation generating unit  110 , which comprises a multiplicity of radiation sources  112 , for example laser diodes, is preferably provided for producing the exposure beams  56  separately from the exposure device  30 , the radiation generated by each of the radiation sources  112  being coupled into a light guide  114 , which runs from the radiation generating unit  110  to the exposure device  30  and has an end face which forms the radiation exit region  54 , from which the exposure beams  56  emerge. 
         [0081]    Locating the radiation generating unit  110  separately from the exposure units  50  has the advantage that this provides the possibility of disposing the radiation sources  112  optimally for their operation and of dissipating the heat generated by them optimally, without this having any accompanying thermal influence on the exposure device  30 . 
         [0082]    Rather, the exposure device  30  is thermally isolated completely from the radiation generating unit  110 , and there is consequently no risk of impairment of the precision in the region of the exposure device  30  being brought about by thermal effects caused by the radiation generating unit  110 . 
         [0083]    The radiation generating unit  110  may in this case be disposed at a distance above the exposure device  30 , but there is also the possibility of disposing the radiation generating unit  110  to the side of the machine base  10 , for example alongside the control unit  100 , if the light guides  114  are made sufficiently long. 
         [0084]    As already explained, for the radiation generating unit  110  there is the possibility on the one hand of exactly sensing the rotational position of the reflective body  70  by way of the respective sensors  98  that are associated with the respective deflection unit  64 , and consequently being able to determine in which exposure spot position  90  the respective exposure spot  42  produced is located along the path of deflection AS at the respectively determined point in time, and consequently of deciding whether or not an exposure of the photosensitive layer  24  is to be carried out in this exposure spot position  90 , and on the basis of this decision activating the radiation source  112  that is provided for producing the respective exposure spot  42  in such a way that it produces radiation, which triggers a photochemical effect in the photosensitive layer  24  in the region of the exposure spot  42 , or switching off said radiation source or reducing its intensity to the extent that no photochemical effect occurs in the region of the exposure spot  42  located in the respective exposure spot position  90 . 
         [0085]    In order not only to be able to position the individual exposure spots  42  in the individual exposure spot positions  90  within the path of deflection AS in such a way that they overlap one another—for the production of contiguous structures  26  extending at least with a component in the transverse direction—, in order to be able to produce the contiguous structure  26  by a multiplicity of individual exposure spots  42 , but also to be able to locate in an overlapping manner the exposure spots  42  that can be produced by exposure beams  66  successively following one another in the series direction  53 , the series direction  53  runs at an angle α in relation to the direction of advance  16  such that a straight reference line  120  parallel to the direction of advance  16  and passing through the final exposure spot position  90   1N  of the, for example, first exposure beam  66   1  of an exposure unit  50  is tangent to, preferably intersects, the exposure spot  42   21  in the first exposure spot position  90   21  of the next exposure beam  66   2  following in the series direction  53 , so that, by movement of the final exposure spot  42   1N  in the direction of advance  16  to the advanced position of the first exposure spot  42   21  of the next-following exposure beam  66   2 , the two exposure spots  42   1N  and  42   21  can be disposed overlapping one another, and consequently the exposure spots  42   2  of the second exposure beam  66   2  can also be used together with the exposure spots  42   1  of the first exposure beam  66   1  for producing the contiguous structure  26 . 
         [0086]    This relative disposition of the respectively final exposure spot  42  of an exposure beam  66  with respect to the respectively first exposure spot  42  of the next-following exposure beam  66  is provided in the case of all the exposure beams  66  and exposure spots  42  of an exposure unit  50 , so that in theory all the exposure spots  42  of this exposure unit  50  can be used for producing a contiguous structure  26  extending with a component in the transverse direction  38  over the entire extent of this exposure unit  50  in the transverse direction  38 . 
         [0087]    In the same way as described in conjunction with the disposition of the exposure spots  42  produced by different exposure beams  66 , the plurality of exposure units  50   a ,  50   b ,  50   c  etc. are also disposed in relation to one another in such a way that, as represented for example in  FIG. 3 , a straight reference line  120  that is parallel to the direction of advance  16  and passes through the final exposure position  90   nN  of a first exposure unit, for example the exposure unit  50   a , is tangent to, or intersects, the exposure spot  42   11  of the first exposure position  90   11  of the next exposure unit following in the transverse direction  38 , for example the exposure unit  50   b , so that the exposure spots that can be formed by a plurality of exposure units, for example the exposure units  50   a  and  50   b , can also be used for producing a contiguous structure  26 , in that the exposure spots  42  of one exposure unit, for example the exposure unit  50   a , are positioned in an overlapping manner and the final exposure spot  42   nN  of the final exposure beam  66   n  can be disposed in an overlapping manner with the first exposure spot  42   11  of the first exposure beam  66   1  of the next-following exposure unit, for example the exposure unit  50   b , in an overlapping manner. 
         [0088]    On condition that the exposure region  40  extends in the transverse direction  38  over the entire width of the photosensitive layer  24 , or at least over a region of the photosensitive layer  24  that is intended for exposure and for producing structures  26 , contiguous structures or then again non-contiguous structures  26  can be produced in the entire region of the photosensitive layer  24 . 
         [0089]    Since all the exposure units  50  of the exposure device  30  are disposed in such a way in relation to one another, there is consequently the possibility, by using the advancing movement  16 , of producing, on the photosensitive layer  24 , over the entire transverse direction  38  thereof and over the entire longitudinal direction  36 , structures  26  which are contiguous in any desired regions and may run both in the longitudinal direction  36  and in the transverse direction  38  or at any angle with respect to these directions. 
         [0090]    For this purpose, the control unit  100  senses both the position of the photosensitive layer  24  in the direction of advance  16 , by detecting the position of the object carrier  14 , and the positions of the individual producible exposure spots  42  along the path of deflection AS, by the rotational position of the reflective bodies  70 , and is consequently capable, by suitable activation of the respective radiation source  112  at the suitable point in time, additionally of generating an exposure spot  42  at any location of the region of the photosensitive layer  24  that is intended for exposure, this preferably taking place by suitable activation of the radiation sources  112  in the course of a single movement of the object carrier  14  in the direction of advance. 
         [0091]    For sufficient accuracy when positioning the exposure spots  42  to produce the structures  26 , it is advantageous if the speed in the direction of advance  16  is only so great that the exposure spots  42  produced by an exposure beam  66  from two reflective surface regions  78  successively following one another in the circumferential direction  76  are offset with respect to one another by at most half a diameter, still better by at most a quarter or a fifth of a diameter, of the exposure spots  42 , that is to say overlap to a considerable extent.