JP4326361B2 - Light intensity uniformizing optical system - Google Patents

Description

  The present invention relates to a light intensity uniformizing optical system capable of uniforming an illuminance distribution on an irradiation surface and changing an irradiation area on a work such as a printed wiring board as an object to be exposed.

  In general, for example, an exposure apparatus having a configuration shown in FIG. 5 is known. The conventional exposure apparatus 100 includes a light source unit 20 having a lamp 21 for ultraviolet irradiation and an elliptical reflecting mirror (spheroid mirror) 22, a planar reflecting mirror 41 that reflects irradiation light from the light source unit 20, An illuminance distribution uniformizing mechanism (lens array) 30 that equalizes the illuminance distribution on the irradiation surface of the illuminating light reflected from the flat reflecting mirror 41, and the irradiation light from the illuminance distribution uniformizing mechanism 30 as parallel light. A collimation mirror 42 that is reflected on the substrate, a holding frame 50 that holds the mask M that is disposed in the optical path of the irradiation light that is reflected from the collimation mirror 42, and a work that is disposed at a position facing the mask M held on the holding frame 50. And an alignment table 60 on which W is placed.

  6A and 6B, the illuminance distribution uniformizing mechanism 30 of the exposure apparatus 100 includes a first lens array 31 in which a plurality of convex lenses are arranged on the same plane, and the first lens. A second lens array 32 in which a plurality of convex lenses are arranged on the same plane at a position facing the array 31 and a moving mechanism 33 that allows the first lens array 31 to move in the optical axis direction are provided.

  For this reason, when the exposure apparatus 100 performs the exposure operation with the first lens array 31 of the illuminance distribution uniformizing mechanism 30 as the initially set positional relationship, the irradiation area with respect to the workpiece W in the alignment table 60 becomes maximum, and the light source unit 20. The entire workpiece W can be exposed at a time by the irradiation light irradiated from. In addition, the exposure apparatus 100 moves the first lens array 31 of the illuminance distribution uniformizing mechanism 30 in the optical axis direction by the moving mechanism 33, so that the position of the incident surface of the irradiation light incident on the illuminance distribution uniformizing mechanism 30 is determined. In other words, the irradiation area irradiated with the irradiation light (for example, 1/4 of the total exposure area) is reduced, and a predetermined region of the workpiece can be exposed.

In the illuminance distribution uniformizing mechanism 30, incident light is divided into light by the lens elements constituting the lens arrays 31 and 32, and as a result, a single light source is emitted on the emission side of the illuminance distribution uniformizing mechanism 30. By dividing into light sources corresponding to the number of lens elements and canceling the “unevenness” of the intensity with respect to the irradiation light, the illuminance distribution becomes almost uniform in the irradiation range.
JP 2001-125203 A

However, the configuration of the illuminance distribution uniformizing mechanism in the conventional exposure apparatus has the following problems.
In the configuration of the illuminance distribution uniformizing mechanism in the conventional exposure apparatus, it is necessary to quickly perform the exposure processing time of the work while ensuring an appropriate exposure state. However, in the configuration in which only the first lens array is moved, In order to change the setting conditions as the illuminance distribution uniformization mechanism that has been set, each lens element of the first lens array is maintained to be a predetermined optical path of each lens element of the second lens array in the originally adjusted range. become unable. Therefore, in the exposure apparatus, as a result of moving the first lens array, the irradiation area becomes, for example, 1/4, but the condensing rate is not proportionally quadrupled, but is about 1.6 times, and the work piece is the same. The exposure irradiation time for the sheet is significantly longer than the originally scheduled time. For example, if the exposure time for the exposure region takes about 5.8 seconds, and the exposure surface of one workpiece has n surfaces (for example, 2, 4 and 6 surfaces), 5.8 seconds × It will take n times as long.

  Further, in the configuration of the illuminance distribution uniformizing mechanism in the conventional exposure apparatus, since the setting condition of the preset fly lens is changed when the irradiation area is changed, the light entering the predetermined lens is adjacent to the lens. Then, the light that has not been set from the adjacent lens is emitted from the illuminance distribution uniformizing mechanism in a state of being overlapped. Therefore, on the alignment table side on which the workpiece of the exposure apparatus is placed, unnecessary light is scattered on the surface other than the irradiation surface of the workpiece, and light other than the parallel light that appropriately contributes to the exposure work performs useless irregular reflection. Therefore, there is a high possibility that the exposed surface of the workpiece will be adversely affected, which is inconvenient for the exposure work.

  The present invention was devised in view of the above-mentioned problems, and exposure exposure time is minimized (improvement of light collection rate) without impairing the uniformity of illuminance distribution. Another object of the present invention is to provide a light intensity uniformizing optical system that minimizes the scattering of light and that can be changed in irradiation area with a simple configuration.

The light intensity uniformizing optical system according to the present invention has the following configuration in order to achieve the above object. That is, in a light intensity uniformizing optical system that is arranged in an optical path of light from a light source unit to a work and uniformizes an illuminance distribution of light emitted from the light source unit, the light intensity uniformizing optical system includes a plurality of convex lenses. Are arranged on the same plane, a second lens array in which a plurality of convex lenses are arranged on the same plane facing the first lens array at a predetermined distance, and the second lens array and A plurality of concave lenses are arranged on the same plane at a position between the lens arrays of the first lens array so as to be opposed to the two lens groups and disposed in the optical path or removably from the optical path . An illuminance distribution of 80% or more and an illuminance of 120 mW / cm ² or more when the exposure area and the irradiated surface of the workpiece are 100% of the same ratio. The focal length of each lens array is -2.5 <(when the focal length of the third lens array is f1 and the focal length of the first lens array and the second lens array is f2. f2 / f1) <-0.5 ... It was set as the structure which is the range represented by Formula (1).

With this configuration, the light intensity uniformizing optical system has a reference set angle from the first lens array through the second lens array when light is incident on the first lens array and the second lens array. The light is emitted so as to spread. Further, in the light intensity uniformizing optical system, when the third lens array is disposed between the first lens array and the second lens array via the moving means, the third lens is added, so that the angle is smaller than the reference setting angle. The light is emitted from the light intensity uniformizing optical system at a set angle. Therefore, the third lens array can be arranged in the optical path between the first lens array and the second lens array or can be retracted from the optical path, so that the exposure area on the irradiation surface can be changed (note that the irradiation surface and Is a surface at the position where the workpiece is placed, irradiated by irradiation light (including through another optical system) emitted from the light intensity uniformizing optical system. The surface of the workpiece to be exposed). With this configuration, in the light intensity uniformizing optical system, f2 / f1, which is the ratio of the focal length f1 of the third lens array and the focal length f2 of the first and second lens arrays, is -2. Since it is set to be larger than 5, the illuminance distribution state on the irradiation surface is within the allowable range of the exposure work in the periphery and the center. In addition, since f2 / f1 is set to be negatively larger than −0.5, the illuminance distribution state on the irradiation surface is originally formed without forming the irradiation surface in a range larger than the originally set area. The exposure range is within the set irradiation area. Note that the minus sign is used because a concave lens is used.

According to a second aspect of the present invention, there is provided a light intensity uniformizing optical system that is disposed in an optical path of light from a light source unit to a work and uniformizes an illuminance distribution of light emitted from the light source unit. The homogenizing optical system includes a first lens array in which a plurality of convex lenses are arranged on the same plane, and a second lens in which the plurality of convex lenses are arranged on the same plane at a predetermined distance so as to face the first lens array. An array, and a second lens array and a position between the lens arrays of the first lens array, which are disposed on the optical path so as to be opposed to both lens groups, or can be retracted from the optical path via moving means, a plurality of the third lens array and the are arranged concave lens comprises, in illuminance distribution of 80% or more when the irradiation surface and the exposed region of the workpiece is 100% identical proportions, illuminance 120 If it is W / cm ² or more, the distance between the two lens at the central optical axis position of the convex lens of the convex lens and the second lens array of the first lens array and d1, the third lens array is the first lens array And a distance between both lenses at the central optical axis position of the convex lens of the first lens array and the concave lens of the third lens array when arranged at the position between the lens arrays of the second lens array, and When the distance between both lenses at the central optical axis position of the convex lens of the two-lens array and the concave lens of the third lens array is d3, (d2 + d3) / 2 <d1 (2), 0.5 <d2 / d3 <2 ... Each lens array is arranged within the range of the distance represented by Expression (3).

  With this configuration, the light intensity uniformizing optical system sets the distance between the lens arrays within the range indicated by Expression (2) and Expression (3), and thus d1 is set to d2 / d3. On the other hand, by making the ratio smaller than 0.5, the light collection rate on the irradiation surface is within an appropriate range, and by setting d2 / d3 within a predetermined range, the illuminance at the time of light collection on the irradiation surface The distribution range can be secured within a range that can be adjusted within an allowable range for the exposure work.

Further, the invention according to claim 3 is the light intensity uniformizing optical system, wherein one of the first lens array and the second lens array arranged on the light incident side is adjusted and moved in the optical axis direction. It was set as the structure supported by the adjustment movement means for doing.
With this configuration, the light intensity uniformizing optical system is arranged on the incident light incident side in the optical axis direction by the adjustment moving unit. For example, the first lens array is disposed on the incident light incident side. When adjusted and moved, the first lens array and the second lens array have a more appropriate positional relationship with respect to the state where the third lens array is arranged, and the irradiation light irradiated from the light intensity uniformizing optical system is The irradiation surface is reached in a more appropriate state.

  Furthermore, in the invention described in claim 4, the first lens array, the second lens array, and the third lens array are held by respective holders of holding means, and the moving means and the adjusting moving means are: The holding means is supported by the holding means, and the holding means includes a shield part that prevents dust from adhering to a position directly above the moving means when the third lens array is moved to the retracted position, and the first lens array and The cover is configured to be a light intensity uniformizing optical system in which a cover portion that does not allow dust to adhere to the second lens array is provided on one end side of the shield portion.

According to the first aspect of the present invention, in the light intensity uniformizing optical system, the third lens array is arranged in the optical path between the lens arrays of the first lens array and the second lens array by the moving means, or can be retracted from the optical path. Since it is provided, the configuration is simple, there is no blur in the optical axis direction, and the range of the exposure area on the irradiation surface can be adjusted without adjusting the preset first and second lens arrays. it can. Further, in the light intensity uniformizing optical system, the condensing rate is 2.5 when the entire exposure area is changed to, for example, a 1/4 exposure area without impairing the uniformity of the illuminance distribution. The light collection rate can be improved by about 1.5 times compared to the conventional one. In the light intensity uniformizing optical system, since the focal lengths of the first lens array, the second lens array, and the third lens array are set to a predetermined range, an appropriate light collection rate range on the irradiation surface is obtained. Irradiation light can be emitted in such a way (in addition, an appropriate light collection rate range is such that the exposure area and the irradiation surface are closer to the same (ratio is 1), and the distribution state of irradiation light [ (Illuminance distribution and illuminance] are within the preset tolerance range. )

According to the second aspect of the present invention, in the light intensity uniformizing optical system, the distance between the first lens array, the second lens array, and the third lens array is set to a predetermined range. The range of the irradiation area can be appropriately ensured while maintaining the above.

According to the third aspect of the invention, in the light intensity uniformizing optical system, when the third lens array in which the concave lenses are arranged is disposed in the optical path between the first lens array and the second lens array in which the convex lenses are arranged. In addition, by moving the first lens array arranged on the light incident side to an appropriate position via the adjustment moving means, the light collection rate can be further improved as compared with the conventional one (in addition, The proper position means a position where the distribution state of the irradiation light on the irradiation surface falls within a preset allowable range, and here is a position where the illuminance distribution on the irradiation surface and the condition that the illuminance is not less than a predetermined value can be cleared. ).

According to the fourth aspect of the present invention, in the light intensity uniformizing optical system, dust is not attached to each lens array when the moving means or the like is operated by the cover part and the shield part of the holding means.

  For example, in the case of use in an exposure apparatus, when the exposure operation is performed once for the entire exposure area of the workpiece, the third lens array is retracted from the first lens array and the second lens array. In addition, when the work is small as compared with the work using the entire surface of the mounting table, or when there are a plurality of exposure areas and each work is performed one by one, the third lens array is placed between the first lens array and the second lens array. This is done in a state where Therefore, the exposure apparatus does not need to move and adjust each lens array in the optical axis direction in the case of a workpiece that can appropriately perform the exposure operation in the irradiation state by arranging the third lens array.

  In addition, for example, when used in an exposure apparatus, the third lens is disposed between the first lens array and the second lens array, so that unnecessary light for the work exposure work is provided around the work exposure area. Can be minimized. Furthermore, in the exposure apparatus, the light collection rate can be improved while maintaining the uniformity of the illuminance distribution, so the exposure time in the exposure area of the workpiece can be minimized and compared with conventional exposure apparatuses. Thus, it becomes possible to achieve a processing speed of 2.5 times.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The light intensity uniformizing optical system will be described as being used in an exposure apparatus. FIG. 1 is a schematic diagram showing a configuration of the entire exposure apparatus, FIGS. 2A and 2B are schematic diagrams schematically showing the state of irradiation light emitted from a light intensity uniformizing optical system, and FIG. ), (B) are cross-sectional views showing the operation of the light intensity uniformizing optical system.

  As shown in FIG. 1, the exposure apparatus 1 includes a light source unit 4 having a discharge lamp 2 arranged at a first focal position of an elliptical mirror 3, and a first light source that reflects irradiation light emitted from the light source unit 4 in a predetermined direction. The one-plane reflecting mirror 5A, the light intensity uniformizing optical system 6 arranged in the optical path of the first plane reflecting mirror 5A, and the irradiation light emitted from the light intensity uniformizing optical system 6 are set in a preset optical path. A second plane reflecting mirror 5B that reflects along, a collimation mirror 5C that reflects the irradiation light reflected from the second plane reflecting mirror 5B as parallel light, and an optical path of the irradiation light reflected from the collimation mirror 5C. A mask holding mechanism 10 for holding the mask M and a mounting table 11 for mounting the workpiece W at a position facing the mask M held by the mask holding mechanism 10 are mainly provided.

  As shown in FIG. 1, the light intensity uniformizing optical system 6 is provided on a housing frame (not shown) of the exposure apparatus 1 by a support member (not shown), and as shown in FIG. 3, the first lens array 6A. And a basic lens array section 6D having the second lens array 6B, and a third lens provided so as to face or be retracted between the first lens array 6A and the second lens array 6B as the basic lens array section 6D. The lens arrays 6A, 6B, and 6C are held by the holding means 8, respectively. The lens array is a lens in which convex lenses or concave lenses are arranged on the same plane.

In the first lens array 6A, a plurality of convex lenses 6a are arranged on the same plane (here, 5 × 4 in length and width) and are held by the holder 8a of the holding means 8. The convex lenses 6a of the first lens array 6A have the same focal length.
In the second lens array 6B, a plurality of convex lenses 6b are arranged on the same plane (here, 5 × 4 in length and width) and are held by the holder 8b of the holding means 8. Each lens 6b of the second lens array 6B has the same focal length. Here, the focal lengths f2 of the convex lens 6a and the convex lens 6b are set to be the same. The base end surface 8d of the holder 8b is configured as a guide in the moving means 7 of the third lens array 6C described later.

  The holder 8 a that holds the first lens array 6 </ b> A is supported by an adjustment moving unit 9 that can move in the optical axis direction from the housing side of the holding unit 8. The holder 8b that holds the second lens array 6B is fixed to the housing side of the holding means 8. Note that the second lens array 6B is always fixed in position and does not move in the optical axis direction.

  Furthermore, the adjustment moving means 9 that supports the holder 8a so as to be movable in the optical axis direction has a support portion 9a that supports the holder 8a and a moving portion 9b that moves (rotates) the support portion 9a. And here, the holder 8a is attached in the direction orthogonal to the support part 9a. Here, a servo motor or the like is used as the moving portion 9b, and a feed screw is used as the supporting portion 9a, and the holder 8a is configured to move along the optical axis direction. When the holder 8a is moved, the proximal end portion of the holder 8a is moved using the upright portion 8f of the holding means 8 as a guide. Further, a guide for moving the holder 8a may be provided as appropriate at other positions.

  The third lens array 6C is held by the holder 8c of the holding means 8 with a plurality of concave lenses 6c arranged in the same plane (here, 5 × 4 in length and width). The concave lenses 6c of the third lens array 6C are set to have the same focal length.

  The third lens array 6C is configured such that the holder 8c is moved by the moving means 7 so as to be disposed or retracted between the lens arrays of the first lens array 6A and the second lens array 6B. The moving means 7 includes a flange portion 7a provided on the holder 8c, a feed screw 7b as a support portion supported by the flange portion 7a of the holder 8c, and a servo motor 7c for rotating the feed screw 7b. . A cover 8e for preventing dust from adhering to the first lens array 6A and the second lens array 6B when the moving means 7 is operated is provided on one end side of the feed screw 7b. It is provided at a predetermined position 8b. Further, a shield part 8g for preventing dust from adhering to the third lens array 6C is provided immediately above the feed screw 7b, and the shield part 8g is inserted into a through hole provided in the flange part 7a. The flange portion 7a can be moved in the state.

In the third lens array 6C, when the servo motor 7c is operated and the feed screw 7b is rotated, the flange portion 7a is guided along the base end surface 8d of the holder 8b, and the first lens array 6A and the second lens array are retracted from the retracted position. It becomes possible to move to a position facing 6B. When the third lens array 6C is disposed between the lens arrays 6A and 6B, the third lens array 6C is set so that the optical axes of the biconvex lenses 6a and 6b coincide with the optical axis of the concave lens 6c. Further, in the third lens array 6C, the servomotor 7c is actuated to rotate the feed screw 7b in the opposite direction, whereby the flange portion 7a is guided along the base end surface 8d of the holder 8b, and between the lens arrays 6A and 6B. To the retreat position where the optical path is not affected.

  When the focal length of the third lens array 6C is f1, and the focal lengths of the convex lenses 6a and 6b of the first lens array 6A and the second lens array 6B are f2, -2.5 <f2 / f1 < It is configured to be within a range of −0.5. When f2 / f1 deviates from -2.5 to the minus side (when the focal length of the concave lens is small), there is insufficient light to irradiate a preset irradiation surface (exposure area).

  In addition, when f2 / f1 deviates from “−0.5” to the “0” side or the plus side (when the focal length of the concave lens is large), a light beam irradiated to a preset irradiation surface (exposure region). As a result, the illuminance of the irradiation surface (exposure area) set in advance is lowered. Therefore, the focal length f1 of the concave lens 6c is within the range of the formula (1) represented by -2.5 <f2 / f1 <-0.5 in relation to the other convex lenses 6a and 6b. It is more preferable that −1.2 <f2 / f1 <−0.8, and the best range is −1.0 <f2 / f1 <−0.9.

In addition, as shown in Table 1, -2.5 <f2 / f1 <-0.5 ... In Formula (1), when it is -2.5 or less, the illumination intensity in an irradiation surface will be 150 mW / cm < ² >, and The illuminance distribution on the irradiated surface is 80%, which is an allowable range. However, if the numerical value deviates from -2.5 to the mass side, for example, -3.5, the value of the illuminance distribution becomes small, which is inconvenient (illuminance 80% or more as a guide for distribution). Further, in Formula (1), if the numerical value deviates from “−0.5” to “0”, for example, −0.25, the illuminance distribution is within the allowable range, but the illuminance is 100 mW / cm ² , which is inconvenient. (120mW / cm ² or more as a measure of illuminance)

  Further, as shown in FIG. 3B, the distance from the lens surface at the central optical axis position of the convex lens 6a of the first lens array 6A to the lens surface at the central optical axis position of the convex lens 6b of the second lens array 6B is d1. The distance from the lens surface at the central optical axis position of the convex lens 6a of the first lens array 6A to the lens surface at the central optical axis position of the concave lens of the third lens array 6C is d2, and the second lens array 6B The distance from the lens surface at the central optical axis position of the convex lens 6b to the lens surface at the central optical axis position of the concave lens of the third lens array 6C is d3. The relationship between the inter-lens distances d1, d2, and d3 is within the condition range of (d2 + d3) / 2 <d1 (2) and 0.5 <d2 / d3 <2 (3).

  That is, in the case of (d2 + d3) / 2 <d1, the light collection rate becomes too large, so that it is impossible to appropriately control the irradiation surface. When d2 / d3 ≦ 0.5, the illuminance distribution on the irradiation surface is less than a required value, for example, less than about 80% illuminance distribution, and also when d2 / d3 ≧ 2, The illuminance distribution on the surface is lower than a required value, for example, about 80% of the illuminance distribution. Ideally, d2 = d3.

As shown in Table 2, (d2 + d3) / 2 <d1 ... when satisfying formula (2), the illuminance is 158mW / cm ² becomes the irradiated surface, a 120 mW / cm ^2, which is a measure of illumination sufficient It is a satisfactory value. However, when (d2 + d3) / 2 = d1 or (d2 + d3) / 2> d1 is not satisfied, the illuminance is 90 mW / cm ² or less, which is inconvenient.

Furthermore, as shown in Table 3, it is necessary to satisfy the formula (2) and also satisfy 0.5 <d2 / d3 <2 ... formula (3). When the formula (3) is satisfied, that is, When 0.5 <d2 / d3, the illuminance distribution on the irradiated surface is 84%, which exceeds 80% as a guide. However, for example, “0.3” below “0.5” is inconvenient because the value is 55%. Further, when d2 / d3 <2, the illuminance distribution on the irradiated surface is 81%, which exceeds 80% as a guideline. However, when “2” or more, for example, “3”, 52.3%. Value and inconvenient.
Next, the operation of the light intensity uniformizing optical system 6 will be described with reference to FIGS. For the sake of explanation, FIG. 2 will be described in an arrangement that ignores the vertical and horizontal directions that are actually installed.

As shown in FIG. 2A, in the light intensity uniformizing optical system 6, in the basic lens array unit 6D using the first lens array 6A and the second lens array 6B, the irradiated light is incident from the first lens array 6A. Then, the light is emitted at an angle θ1 having a predetermined spread with respect to the optical axis center Ce via the second lens array 6B. At this time, the light intensity uniformizing optical system 6 is in a state in which the third lens array 6C is disposed at the retracted position, as shown in FIG. Note that, on the irradiation surface when the basic lens array unit 6D is used, the irradiation length side is a.

  Next, as shown in FIG. 2B, when changing the range of the irradiation surface while maintaining the illuminance distribution, the light intensity uniformizing optical system 6 includes a basic lens array unit 6D, a third lens array, and the like. 6C is used. That is, by setting the third lens array 6C to face between the lens arrays 6A and 6B from the retracted position, the irradiation light incident on the first lens array 6A is emitted from the third lens array 6C and the second lens array 6C. The light is emitted through the lens array 6B, and is emitted with an irradiation angle θ2 smaller than the irradiation angle θ1 (see FIG. 2A) with respect to the optical axis center Ce. The irradiation surface in the light intensity uniformizing optical system 6 at this time is in a range of irradiation length side a / 2 (for example, irradiation area of 1/4).

  In addition, when moving the 3rd lens array 6C between both lens arrays 6A and 6B from a retracted position, it has performed here by the following procedures as an example. That is, from the state shown in FIG. 3A, as shown in FIG. 3B, the light intensity uniformizing optical system 6 moves the third lens array 6C from the retracted position by the moving means 7 so that both lens arrays 6A. , 6B, and the first lens array 6A is adjusted and moved to a preset position by the adjustment moving means 9. Here, in the light intensity uniformizing optical system 6, when the third lens array 6C is disposed between the lens arrays 6A and 6B, the positional relationship between the lens arrays 6A, 6B, and 6C is expressed as d2 = d3 is set such that d1> (d2 + d3) / 2. Further, in the light intensity uniformizing optical system 6, the first lens array 6A is adjusted and moved in the direction of the optical axis so that the illuminance distribution on the irradiation surface is optimized by arranging the third lens array 6C. It is.

  As shown in FIGS. 2A and 2B and FIGS. 3A and 3B, in the light intensity uniformizing optical system 6, the relationship of d2 = d3 is obtained by adjusting and moving the first lens array 6A. As described above, the first lens array 6A is adjusted if the relationship of the above-described formulas (1) to (3) is maintained and the required illuminance distribution on the irradiated surface is within an allowable range. There is no need to move.

Further, on the assumption that the required illuminance distribution is within the allowable range, as shown in FIG. 4, the first lens array 6A may not be adjusted and moved. FIGS. 4A and 4B are cross-sectional views showing operation states in another configuration of the light intensity uniformizing optical system. Note that the light intensity uniformizing optical system shown in FIG. 4 is in a state where there is no adjustment moving means 9 with respect to what has already been described, so only the operation will be described with the same reference numerals.

  As shown in FIG. 4 (a), the light intensity uniformizing optical system 6 has a basic lens array section 6D that is set first, and the third lens array 6C is replaced with a double lens array 6A as shown in FIG. 4 (b). , 6B, the third lens array 6C is arranged in advance at a position where d2 = d3 and is moved via the moving means 7. That is, from the state of the basic lens array section 6D, the third lens array 6C is moved from the retracted position via the moving means 7, and the optical axis centers of the lenses 6a, 6b, 6c are located between the lens arrays 6A, 6B. They are arranged to match.

  In the light intensity uniformizing optical system 6 in the state where the third lens array 6C is arranged, the light is incident from the first lens array 6A so that, for example, the irradiation area of the basic lens array unit 6D is 1/4. Irradiation light is emitted through the third lens array 6C and the second lens array 6B.

  As described above, the light intensity uniformizing optical system 6 performs irradiation by arranging the third lens array 6C so as to face the lens arrays 6A and 6B depending on the required illuminance distribution above a certain level. The area can be changed. Further, the irradiation amount of the irradiation light on the irradiation surface in the state where the third lens array 6C is arranged is, for example, 2.5 when compared with the case where only the basic lens array unit 6D is provided when the irradiation area is 1/4. It will be around double. Further, when the first lens array 6A is adjusted and moved by the adjustment moving means 9, it becomes 2.5 times or more.

  Here, the light intensity uniformizing optical system 6 has been described on the assumption that the irradiation area is changed from 1 to 1/4. However, the ratio of the irradiation area to be changed is from 1 to 1/2, and from 1 to 1. It may be 1/6 or 1/8. When the ratio of the irradiation area is changed, the positions of the lens arrays 6A, 6B, 6C at the focal lengths of the lens arrays 6A, 6B, 6C set in advance are determined. The three-lens array 6C or the first lens array 6A is arranged. The third lens array 6C may be configured to move by being guided by the guide mechanism, and is not limited to the configuration of the guide mechanism.

  The adjustment moving means 9 and the moving means 7 are only examples, and may be a cylinder mechanism or the like as long as the first lens array 6A or the third lens array 6C can be adjusted and moved appropriately. You may use what comprises the structure of.

Moreover, the light intensity uniformizing optical system 6 already described can be applied to, for example, the exposure apparatus 1 shown in FIG. 1. As the form of the exposure apparatus 1, although not shown, a handler is provided from carry-in to carry-out. Automatic exposure apparatus (both work and single side) carried out via, so-called semi-automatic exposure equipment (both work and single side) carried by an operator, vertical exposure apparatus or work exposure apparatus in which work is arranged in the vertical direction Any type of exposure apparatus can be used as long as the work to be handled in the above is a roll form, a sheet form (plate form, sheet form) or the like using the light intensity uniformizing optical system 6. In the exposure apparatus 1, a mask holding mechanism 10 and a mounting table 11.
, A suction mechanism 12, an alignment mechanism 13, a vertical movement mechanism 14, a CCD camera 15, a vacuum contact mechanism 16, a shutter mechanism 17, a monitor Mo (mask mark Mm, work mark Wm), and the like. Needless to say, the light intensity uniformizing optical system 6 can be applied to configurations other than the exposure apparatus 1.

  In the case of the exposure apparatus 1, the condensing rate with respect to the exposure area of the workpiece W is 2.5 times that in the state of FIG. Therefore, the irradiation time for each exposure area in the exposure apparatus 1 may be about 4 seconds when, for example, 500 mJ is required, and is about 16 seconds because there are four exposure areas in one workpiece W. Therefore, for example, by using the light intensity uniformizing optical system 6, the exposure apparatus 1 can perform an exposure operation with a quick tact time even if the exposure area of the workpiece W changes, and can be applied to the irradiation surface. The exposure operation can be performed in a state where unnecessary light scattering is also minimized.

1 is a block diagram schematically showing the overall configuration of an exposure apparatus according to the present invention. (A), (b) is a schematic diagram which shows typically the state of the irradiation light inject | emitted from the light intensity uniformization optical system which concerns on this invention. (A), (b) is sectional drawing which shows operation | movement of the light intensity uniformization optical system based on this invention. (A), (b) is sectional drawing which shows the operation state in the other structure of the light intensity uniformization optical system based on this invention. It is a block diagram which shows typically the structure of the conventional exposure apparatus. It is a block diagram which shows the moving mechanism in the conventional light intensity equalization optical system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 2 Discharge lamp 3 Elliptical reflector 4 Light source part 5 Reflective optical system 6 Light intensity uniformizing optical system 6A 1st lens array 6B 2nd lens array 6C 3rd lens array 6D Basic lens array part 6a Convex lens 6b Convex lens 6c Concave lens 7 Moving means 8 Holding means 9 Adjustment moving means 10 Mask holding mechanism 11 Placement table 12 Suction mechanism 13 Alignment mechanism 14 Vertical movement mechanism 15 CCD camera 16 Vacuum contact mechanism 17 Shutter mechanism M Mask W Work Mo monitor

Claims (4)

In the light intensity uniformizing optical system that is arranged in the optical path of light from the light source unit to the work and uniformizes the illuminance distribution of the light emitted from the light source unit,
In the light intensity uniformizing optical system, a first lens array in which a plurality of convex lenses are arranged on the same plane, and a plurality of convex lenses are arranged on the same plane facing the first lens array with a predetermined distance therebetween. A second lens array and a position between the lens array of the second lens array and the first lens array , arranged in the optical path facing the both lens groups, or provided through a moving means so as to be retractable from the optical path ; A third lens array in which a plurality of concave lenses are arranged on the same plane,
When the illuminance distribution is 80% or more and the illuminance is 120 mW / cm ² or more when the exposure area and the irradiation surface of the workpiece are 100% of the same ratio ,
The focal lengths of the lens arrays are: when the focal length of the third lens array is f1, and the focal length of the first lens array and the second lens array is f2.
−2.5 <(f2 / f1) <− 0.5 (1)
A light intensity uniformizing optical system having a range represented by In the light intensity uniformizing optical system that is arranged in the optical path of light from the light source unit to the work and uniformizes the illuminance distribution of the light emitted from the light source unit,
In the light intensity uniformizing optical system, a first lens array in which a plurality of convex lenses are arranged on the same plane, and a plurality of convex lenses are arranged on the same plane facing the first lens array with a predetermined distance therebetween. A second lens array and a position between the lens array of the second lens array and the first lens array , arranged in the optical path facing the both lens groups, or provided through a moving means so as to be retractable from the optical path ; A third lens array in which a plurality of concave lenses are arranged on the same plane,
When the illuminance distribution is 80% or more and the illuminance is 120 mW / cm ² or more when the exposure area and the irradiation surface of the workpiece are 100% of the same ratio
The distance between the biconvex lenses at the center optical axis position of the convex lens of the first lens array and the convex lens of the second lens array is d1, and the third lens array is a lens array of the first lens array and the second lens array. A distance between the two lenses at the central optical axis position of the convex lens of the first lens array and the concave lens of the third lens array is d2, and the convex lens and the third lens of the second lens array. When the distance between both lenses at the central optical axis position of the concave lens of the array is d3,
(D2 + d3) / 2 <d1 Formula (2)
0.5 <d2 / d3 <2 Formula (3)
A light intensity uniformizing optical system, wherein each lens array is disposed within a distance range represented by   One of the first lens array and the second lens array arranged on the light incident side is supported by an adjustment moving means for adjusting and moving in the optical axis direction. Item 3. The light intensity uniformizing optical system according to Item 2. The first lens array, the second lens array, and the third lens array are held in respective holders of holding means,
The moving means and the adjustment moving means are held by the holding means,
The holding means includes a shield part that prevents dust from adhering to a position directly above the moving means when the third lens array is moved to the retracted position, and dust is applied to the first lens array and the second lens array. The light intensity uniformizing optical system according to claim 3, wherein a cover portion that is not attached is provided on one end side of the shield portion.

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