JP2003215808A - Multi-exposure drawing device and its lighting mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the use efficiency of illumination light of a multi-exposure drawing device. <P>SOLUTION: The multi-exposure drawing device is provided with a light source unit 22, four fiber bundles 241, 242, 243, and 244 which are optically connected to a plurality of exposure units, and an optical path changing device 23. The optical path changing device 23 is provided with a rotary disk 231, and a 1st reflecting mirror 235 and a 2nd reflecting mirror 237. The rotary disk 231 is rotated by a motor 239 at a fixed speed and the illumination light from the light source unit 22 is distributed to one of the fiber bundles 241, 242, and 243 according to the rotational position of the rotary disk. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drawing apparatus for drawing a predetermined pattern by multiple exposure of a drawing surface using an exposure unit having a large number of modulators, and more particularly to an illumination mechanism thereof.

[0002]

2. Description of the Related Art A drawing apparatus is used for optically drawing a fine pattern or a symbol such as a character on a surface of an object to be drawn. Typically, a photomask is used in manufacturing a printed circuit board by photolithography. It is used for drawing a circuit pattern on an object to be drawn such as a photosensitive film and a resist layer. The circuit pattern is designed by the CAD station,
The vector data is transferred to the drawing device, where it is converted into raster data. The drawing apparatus includes an exposure unit having a large number of modulation elements, and illumination light is introduced into the exposure unit from a light source. Exposure data generated based on the raster data of the circuit pattern is given, and the drawing surface is exposed by modulating the illumination light according to the exposure data.

Since the exposure area that each exposure unit can expose in one exposure is relatively small with respect to the entire area of the drawing surface, in the drawing apparatus, the drawing surface is relative to the exposure unit by a predetermined distance. A method is used in which a circuit pattern is partially drawn by an exposure unit while moving to obtain the entire circuit pattern. At this time, since the exposure data to be given to each modulation element of the exposure unit is updated every predetermined time with the relative movement of the drawing surface, while the new exposure data is calculated, the exposure unit is substantially exposed. Do not do.

However, since the light source for supplying the illumination light to the exposure unit is constantly turned on in order to maintain a constant light output, the illumination light is not used while the exposure data is calculated, and the utilization efficiency of the light source is poor. There is a problem. In particular, when the relative movement distance of the drawing surface is small and the number of exposures is large, the calculation time of the exposure data is relatively increased, so that the utilization efficiency of the light source is significantly reduced and the frequency of replacement of the light source is increased.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve the utilization efficiency of a light source in a multiple exposure drawing device.

[0006]

A multiple exposure drawing apparatus according to the present invention draws a predetermined circuit pattern by multiple exposure using a plurality of exposure units having a large number of modulation elements arranged in a matrix. A multiple exposure apparatus,
The most main feature is to include an optical path changing unit that is provided between a light source that continuously emits illumination light of a constant intensity and an exposure unit and that selectively distributes the illumination light to each of the exposure units.

The optical path changing means supplies illumination light to each of the exposure units for a time required for one exposure operation.

Specifically, the optical path changing means is provided with a rotary plate member which rotates about a predetermined rotation axis and reflects or transmits the illumination light according to the rotation position. Further, it is preferable that the exposure unit repeats the exposure operation at a predetermined exposure cycle, and the rotation cycle of the rotary plate member is an integral multiple of the exposure cycle. Further, it is preferable that the rotary plate member is made of a transparent material, and the reflection region that reflects the illumination light is formed by vapor-depositing aluminum on one surface of the rotary plate member.

Further, the optical path changing means reflects the illumination light reflected by a predetermined reflection region of the rotary plate member toward a region different from the reflection region in the radial direction perpendicular to the rotation axis of the rotary plate member. The first reflecting member may include a first reflecting member and a second reflecting member that reflects the illumination light transmitted through a predetermined transmission region of the rotating plate member toward a region different from the transmitting region in the radial direction of the rotating plate member. Furthermore the first
The reflecting member may be fixed to the incident side of the illumination light with respect to the rotating plate member, and the second reflecting member may be fixed to the opposite side of the first reflecting member with respect to the rotating plate member. A radial direction that is on a plane including the incident optical axis of the illumination light and is inclined by π / 4 [rad] with respect to the incident optical axis, and the reflecting surfaces of the first and second reflecting members are perpendicular to the rotation axis. May be parallel to.

Further, specifically, the rotating plate member includes a first transmitting region that transmits the illumination light incident from the light source when the rotating plate member is in the first rotation position and guides it to the second reflecting member.
When the rotary plate member is in the first rotation position, it is arranged on the rotation axis side of the first transmission region, and further transmits the illumination light that passes through the first transmission region and is reflected by the second reflection member. The second transmission region, which is guided to the exposure unit of the first group, is arranged on the same circumference as the first transmission region when the rotary plate member is in the second rotation position, and transmits the illumination light incident from the light source to the first transmission region. 2 The third transmission region that leads to the reflecting member and the rotating plate member that is the second
The exposure unit of the second group, which is arranged on the rotation axis side of the third transmission region when in the rotation position, transmits the third transmission region and is reflected by the second reflecting member, and further reflects the illumination light. And a first reflection region that is arranged on the same circumference as the first transmission region when the rotary plate member is in the third rotation position and that reflects the illumination light incident from the light source toward the first reflection member. The second reflection area and the rotation plate member are arranged closer to the rotation axis than the second reflection area when the rotary plate member is in the third rotation position.
A fourth transmission area that further transmits the illumination light reflected by the reflection area and the first reflection member and guides it to the exposure unit of the third group, and a second reflection area when the rotary plate member is at the fourth rotation position. A third reflection area, which is arranged on the same circumference and reflects the illumination light incident from the light source toward the first reflection member, and a rotation axis more than the third reflection area when the rotary plate member is at the fourth rotation position. Disposed on the side, the third reflective region and the first
A fourth reflection area may be provided to further reflect the illumination light reflected by the reflection member and guide it to the exposure unit of the fourth group. Further, at this time, it is preferable that the time during which the rotary plate member is kept at the first, second, third or fourth rotational position substantially coincides with the time required for one exposure operation of the exposure unit.

The illumination mechanism of the multiple-exposure drawing apparatus according to the present invention uses a plurality of exposure units having a large number of modulation elements arranged in a matrix to perform multiple exposure to draw a predetermined circuit pattern. And an optical path changing unit provided between the exposure unit and a light source that continuously emits illumination light of a constant intensity, the optical path changing unit selectively distributing the illumination light to each of the exposure units. To do.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a multiple exposure drawing apparatus according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view showing an embodiment of a multiple exposure drawing apparatus according to the present invention. This multiple-exposure drawing apparatus is configured to directly draw a circuit pattern on a photoresist layer formed on a substrate for manufacturing a printed circuit board.

The multiple-exposure drawing apparatus 10 is provided with a base 12 that is installed on the floor surface, and a pair of guide rails 14 are laid in parallel on the base 12 and drawing is performed on the guide rails 14. The table 16 is mounted. The multiple-exposure drawing apparatus 10 is provided with an appropriate driving mechanism (not shown), such as a ball screw driven by a stepping motor or the like, by which the drawing table 16 extends along the pair of guide rails 14 in the longitudinal direction, that is, the X direction. Can be moved relative to.

An object to be drawn 30 is drawn on the drawing table 16.
As a substrate having a photoresist layer is installed as a substrate, the object 30 to be drawn is appropriately fixed on the drawing table 16 by an appropriate clamp means (not shown).

A gate-shaped structure 18 is fixedly mounted on the base 12 so as to straddle a pair of guide rails 14, and a plurality of exposure units on the upper surface of the gate-shaped structure 18 move the drawing table 16. They are arranged in two rows in a first direction (hereinafter, referred to as Y direction) perpendicular to two directions (hereinafter, referred to as X direction). The eight exposure units arranged in the first row are numbered as _{01 01} , 20 ₀₃ , 2 in order from the left side of the drawing.
_Reference numerals 20 ₀₂ , 20 ₀₄ , and 20 ₀₆ indicate from the left side of the drawing eight exposure units indicated by 0 ₀₅ , 20 ₀₇ , 20 ₀₉ , 20 ₁₁ , 20 ₁₃ and 20 ₁₅ and arranged behind them. Two
It is indicated by 0 ₀₈ , 20 ₁₀ , 20 ₁₂ , 20 ₁₄ and 20 ₁₆ .

First row exposure unit 20₀₁, 20₀₃,
20₀₅, 20₀₇, 20₀₉, 20₁₁, 20₁₃And 20₁₅
And the exposure unit 20 in the second row₀₂, 20₀₄, 20₀₆,
20 ₀₈, 20_Ten, 20₁₂, 20₁₄And 20₁₆Is so-called
Staggered arrangement. That is, two adjacent exposure units
The distance between the two is approximately equal to the width of one exposure unit
The exposure unit 20 in the second row that has been set₀₂, 20₀₄Two
0₀₆, 20₀₈, 20_Ten, 20₁₂, 20₁₄And 20₁₆of
The array pitch is the exposure unit 20 in the first row.₀₁, 20₀₃,
20₀₅, 20₀₇, 20₀₉, 20₁₁, 20₁₃And 20₁₅
It is shifted by half a pitch from the array pitch of.

In this embodiment, 16 exposure units 2
Each of _{01 01 to} 20 ₁₆ is configured as a DMD unit, and the reflection surface of each exposure unit is, for example, 1024 × 1.
It is composed of 1310720 micromirrors arranged in a matrix of 280. Each exposure unit 20 ₀₁
20 _16, 1024 along the X-direction, 1280 micromirrors along the Y direction are disposed so as to be arranged.

An appropriate place on the upper surface of the gate structure 18,
For example, the light source device 22 is provided on the left side of the first exposure unit _{20001 in} the drawing. The light source device 22 includes a plurality of LEDs (Light Emitting Diodes) (not shown), and the light emitted from these LEDs is condensed and emitted from the emission port of the light source device 22 as a parallel light flux. In addition to the LED, the light source device 22 may use a laser, an ultra-high pressure mercury lamp, a xenon lamp, a flash lamp, or the like.

The light path changing device 2 is provided at the exit of the light source device 22.
3 is optically connected, and the optical path changing device 23 distributes the parallel light flux emitted from the light source device 22 to each of the ₁₆ optical fiber cables 24 _{01 to} 24 ₁₆ .
16 optical fiber cable 24 _{01-24 16} is extended to each of the 16 exposure unit 20 _{01-20 16,} thereby the light source device 22 each exposure unit 20 ₀₁
A parallel light flux is introduced as illumination light to ˜20 ₁₆ .

The exposure units 200 _{1 to} 20 ₁₆ modulate the illumination light from each of the optical fiber cables 24 _{01 to} 24 ₁₆ according to the circuit pattern to be drawn, and move downward in the drawing, that is, in the gate-like structure 18. The light is emitted toward the object 30 to be drawn on the drawing table 16 which advances inside. As a result, only the portion of the photoresist layer formed on the upper surface of the object 30 to be exposed is illuminated with the illumination light.

[0022] Figure 2, main components of the first exposure unit 20 ₀₁ is conceptually illustrated. Other fifteen exposure units 20 ₀₂ to 20 ₁₆ have the same structure and function as the first exposure unit 20 _01, and a description thereof will be omitted.

[0023] The first exposure unit 20 _01, the illumination optical system 26 and the imaging optical system 28 is incorporated, on the optical path between the two DMD element 27 is provided. The DMD element 27 is a device for operating a square micromirror having a high reflectance, which is formed on a wafer by aluminum sputtering, by an electrostatic field action.

On the silicon memory chip of the DMD element 27, there are 1024 × micromirrors of size C × C.
Laminated in a matrix of 1280, each of these micromirrors operates independently. C is, for example, 20
μm. Here, the micromirror is designated by the code M (m, n)
(1 ≦ m ≦ 1024; 1 ≦ n ≦ 1280). The parameter m indicates the line number along the X-axis direction of the first exposure unit ₂₀₀₀₁ , and the parameter n indicates the line number along the Y-axis direction of the first exposure unit ₂₀₀₀₁ .

The illumination optical system 26 includes a convex lens 26A and a collimating lens 26B, and the convex lens 26A is optically coupled to an optical fiber cable 24 ₀₁ extended from the optical path changing device 23. With such an illumination optical system 26, the luminous flux emitted from the optical fiber cable 24 ₀₁ is DM
A parallel light beam LB that illuminates the entire reflecting surface of the D element 27.
Is molded into. The image forming optical system 28 includes two convex lenses 28.
A and 28C and two convex lenses 28A and 28C
A reflector 28B disposed in between is included, and the magnification of this imaging optical system 28 is set to, for example, 1 × (magnification 1).

[0026] 131 contained in the first exposure unit 20 ₀₁
0720 micro mirrors M (m, n) (1 ≦ m ≦ 1
024; 1 ≦ n ≦ 1280) can be independently independently rotated and tilted about a diagonal line, and two stable postures, specifically, the light fluxes incident on each of them are formed in the imaging optical system 2
8 (hereinafter, referred to as an exposure position) or a second reflection position (hereinafter, referred to as a non-exposure position) that reflects the light flux so as to deviate from the imaging optical system 28. ) Is positioned on either side. Normally, all the micromirrors M (m, n) are positioned at the non-exposure position, but when each corresponding unit exposure area is to be exposed, each is rotationally displaced from the non-exposure position to the exposure position. . Each micro mirror M (m,
The rotational displacement between the non-exposure position and the exposure position in n) is controlled by the exposure data generated based on the raster data of the circuit pattern.

When the arbitrary micro mirror M (m, n) is positioned at the exposure position, the spot light incident thereon is reflected toward the image forming optical system 28 as indicated by the alternate long and short dash line LB1 to form an image. Drawing table 1 by optical system 28
6 is guided to the drawing surface 32 of the object 30 to be drawn. Assuming that the size of the micro mirror M (m, n) is C × C, the magnification of the imaging optical system 28 is equal to,
The reflecting surface of the micro mirror M (m, n) is imaged as an exposure area having an area C × C on the drawing surface 32. The exposure area of area C × C obtained by one micromirror M (m, n) is referred to as unit exposure area U (m, n) in the following description.

On the other hand, when the micro mirror M (m, n) is positioned at the non-exposure position, the spot light is changed to the alternate long and short dash line LB.
2 is reflected toward the light absorbing plate 29 and is absorbed by the light absorbing plate 29, that is, the spot light LB.
2 does not reach the drawing surface 32, and the corresponding region (area C × C) on the drawing surface 32 is not exposed.

[0029] 131 contained in the first exposure unit 20 ₀₁
All 0720 micromirrors M (1,1) to M
When (1024, 1280) is placed at the exposure position,
All micromirrors M (1,1) to M (1024,128
All the spot light reflected from 0) is incident on the imaging optical system 28, and the area on the drawing surface 32 (C × 1024) ×
The area of (C × 1280) is exposed. First
Region may be exposed by all the micromirrors of the exposure unit 20 ₀₁ are hereinafter referred to as entire exposure area Ua _01. One side length C of the unit exposure area U (m, n) is 20μ
If m, the total exposure area Ua _{01 has} an area of 25.6 mm.
(= 1024 × 20 μm) × 20.48 mm (= 128
0 × 20 μm), and the total number of pixels included therein is of course 1024 × 1280.

As is apparent from FIG. 2, the unit exposure area U
(1,1), U (1,2), U (1,3), U (1,
4), U (1,5), ..., U (1,1280) is 1280 micro mirrors M (1, 1) ~M the first line along the Y-axis of the first exposure unit 20 ₀₁ (1, 1280) and the unit exposure areas U (2,1), U
(2,2), U (2,3), U (2,4), U (2
5), ..., U (2,1280) is the first exposure unit 20.
It is obtained from 1280 micromirrors M (2,1) to M (2,1280) of the second line along the Y axis of ₀₁ , and unit exposure areas U (3,1), U (3,2) ), U
(3,3), U (3,4), U (3,5), ..., U
(3,1280) is the first exposure unit 20 ₀₁ of the micromirrors of the third line along the Y-axis M (3, 1) ~M (3,
1280).

The multi-exposure drawing device 10 of this embodiment, a drawing operation of drawing a circuit pattern part by exposure operation of the exposure unit 20 _{01-20 16,} drawing table 16
Along the main scanning direction (X direction) with the entire surface exposure area (U
a ₀₁ ) is repeatedly moved by a distance shorter than the X direction length (C × 1024) of the drawing surface 32.
To be i.e. multiple exposure exposure over a number of times the same region by the exposure unit 20 _{01-20 16.}

The drawing method is a step-and-repeat (Step-and-repeat) method in which intermittent movement of the drawing table 16 and exposure when the drawing table 16 is stopped are alternately repeated to add each drawing area to obtain the entire circuit pattern.
& Repeat) method may be adopted, and drawing table 1
A method may be used in which the drawing operation is simultaneously performed while moving 6 at a constant speed. In the present embodiment, a step-and-repeat method is adopted to facilitate the description. That is,
The multiple-exposure drawing apparatus 10 employs a drawing method of drawing a circuit pattern by multiple exposure while intermittently moving the drawing table 16 at a predetermined movement interval.

For example, when the relative movement distance of the drawing surface 32 per exposure is set to a distance A (for example, A = 4C) that is an integral multiple of the side length C of the unit exposure area U (m, n). the first exposure unit 20 ₀₁ is moved to its positive side along the X-axis by a distance a, the center of the unit exposure region U (m, n) is always coincident on the same point. Therefore, the area of the area C × C of the drawing surface 32 exposed by the leading micromirror M (1,1) in the first column is further reduced to the (4k + 1) th leading micromirror M (4k + 1,1). ), Where 1 ≦ k ≦ 255, a total of 256 times (=
Only 1024 C / A) will be subjected to multiple exposure.

The direction of movement of the drawing surface 32 may be parallel to the X axis, or the drawing surface 32 may be moved with a slight angle with respect to the X axis. For example, when the drawing target 30, that is, the drawing surface 32 is fixed on the drawing table 16 by inclining with respect to the X axis, and the drawing table 16 is moved along the X axis to the negative side by a predetermined distance, each time the movement is made. Unit exposure area U
Not only does (m, n) shift to the positive side along the X axis with respect to the drawing surface 32, but it also shifts to the negative side along the Y axis by a predetermined distance.

In the multiple-exposure drawing apparatus 10 of this embodiment, when a circuit pattern is drawn on the basis of the circuit pattern raster data, whatever the pixel size of the circuit pattern data is, It is possible to draw a circuit pattern. In other words, it can be said that the concept of a pixel for a circuit pattern to be drawn does not exist on the side of the multiple exposure drawing apparatus 10.

For example, the pixel size of raster data is 20
In the case of setting to 1 μm × 20 μm, if “1” is given to any 1-bit data, one pixel area (20 μm × 20
μm), the micromirror M (m, n) corresponding to the unit exposure area U (m, n) is actuated by the 1-bit data to rotate from the non-exposure position to the exposure position,
As a result, such one pixel region (20 μm × 20 μm) is subjected to multiple exposure a total of 256 times.

FIG. 3 is a block diagram of the multiple exposure drawing apparatus 10. As shown in the figure, the multiple exposure drawing apparatus 10 is provided with a system control circuit 34 including a microcomputer. That is, the system control circuit 34 is a central processing unit (CPU), a read-only memory (ROM) for storing programs and constants for executing various routines, and a writable / readable memory for temporarily storing operation data and the like. The multi-exposure drawing apparatus 10 is generally controlled by a memory (RAM) and an input / output interface (I / O).

The drawing table 16 is driven by the drive motor 36 along the X-axis direction. The drive motor 36 is configured as, for example, a stepping motor, and its drive control is performed according to the drive pulse output from the drive circuit 38. A drive mechanism including a ball screw or the like is interposed between the drawing table 16 and the drive motor 36 as described above.
Is symbolically indicated by a dashed arrow.

The drive circuit 38 is a drawing table control circuit 40.
This drawing table control circuit 4 is operated under the control of
0 is connected to the drawing table position detection sensor 42 provided in the drawing table 16. The drawing table position detection sensor 42 detects an optical signal from the linear scale 44 installed along the movement path of the drawing table 16 to detect the position of the drawing table 16 in the X-axis direction. In FIG. 3, the detection of the optical signal from the linear scale 44 is symbolically shown by a dashed arrow.

While the drawing table 16 is moving, the drawing table position detection sensor 42 sequentially detects a series of optical signals from the linear scale 44 and outputs them as a series of detection signals (pulses) to the drawing table control circuit 40. The drawing table control circuit 40 appropriately processes the series of detection signals input thereto, and creates a series of control clock pulses based on the detection signals. Drawing table control circuit 40
Outputs a series of control clock pulses to the drive circuit 38, and the drive circuit 38 creates drive pulses for the drive motor 36 in accordance with the series of control clock pulses. In short, the drawing table 16 can be moved along the X-axis direction with accuracy according to the accuracy of the linear scale 44. Note that such a drawing table 16
The movement control itself is well known.

The drawing table control circuit 40 is connected to the system control circuit 34, so that the drawing table control circuit 40 is controlled by the system control circuit 34. On the other hand, a series of detection signals (pulses) output from the drawing table position detection sensor 42 are also input to the system control circuit 34 via the drawing table control circuit 40, whereby the system control circuit 34.
Then, the movement position of the drawing table 16 along the X axis can be constantly monitored.

The system control circuit 34 is a LAN
It is connected to a CAD station or a CAM station via (Local Area Network), and the vector data of the circuit pattern created there is transferred to the system control circuit 34 from the CAD station or the CAM station. System control circuit 34
A hard disk device 46 is connected as a data storage means to the HDD, and when the vector data of the circuit pattern is transferred from the CAD station or the CAM station to the system control circuit 34, the system control circuit 34 once outputs the vector data of the circuit pattern to the hard disk device 46. Write to and store. The system control circuit 34 also includes a keyboard 4 as an external input device.
8 is connected, and various command signals, various data and the like are transmitted via the keyboard 48 to the system control circuit 34.
Entered in.

The raster conversion circuit 50 is operated under the control of the system control circuit 34. Prior to the drawing operation, the vector data of the circuit pattern is read from the hard disk drive 46 and output to the raster conversion circuit 50. This vector data is converted into raster data by the raster conversion circuit 50, and this raster data is a bit map. It is written in the memory 52. In short, a bit
The map memory 52 stores bit data represented by 0 or 1 as circuit pattern data. Data conversion processing in the raster conversion circuit 50 and data writing in the bit map memory 52 are performed by a command signal input via the keyboard 48.

The read address control circuit 58 reads out the bit data to be given to the exposure units 20 _{01 to} 20 ₁₆ from the bit map memory 52 for each exposure operation, and stores it as the exposure data in the exposure data memory 54. Exposure data is bit data for positioning the micro-mirrors of the individual exposure units 20 ₀₁ to 20 ₁₆ to the exposure position or unexposed position. When a series of read address data is output from the read address control circuit 58 to the exposure data memory 54, predetermined bit data is output from the exposure data memory 54 to the DMD drive circuit 56 in accordance with the read address data. DM
D driving circuit 56 exposure unit 20 _{01-20 16} operates independently on the basis of the bit data, thereby the individual micro mirrors of the exposure unit will be carried out selectively exposing operation. Exposure data is rewritten each time the repeated exposure operation by the exposure unit 20 _{01-20 16.}

Incidentally, in FIG. 3, the exposure operation of each micromirror is symbolically illustrated by a broken line arrow. Also,
Although only one exposure unit is shown in FIG. 3 in order to avoid complication of the drawing, actually, 16 exposure units (20 _{01 to} 20
₁₆ ) Needless to say, they exist and are respectively driven by the DMD drive circuit 56.

The light source device 22 is controlled by the system control circuit 34 and always emits a parallel light beam when the power of the multiple exposure drawing device 10 is turned on. The optical path changing device 23 selectively distributes the parallel luminous flux to each of the exposure units 200 _{1 to} 20 ₁₆ under the control of the system control circuit 34. In FIG. 3, the light flux is symbolically shown by a one-dot chain line.

FIG. 4 is a top view of the gate-shaped structure 18, which shows the optical path changing device 23 and the optical fiber cables 24 ₀₁ to 2 2.
It is a figure which simplifies and shows the connection relation between 4 ₁₆ and exposure units _{2000-1 to} 20 ₁₆ .

16 optical fiber cables 24 _{01 to} 24
₁₆ is four fiber bundles 241, 242 on one end side,
4 of the optical path changing device 23, which are focused on 243 and 244.
It is fixed in three different places. Specifically, the first fiber bundle 241 includes four optical fiber cables 24 ₀₁ , 2
The optical fiber cables 24 ₀₁ , 24 ₀₂ , 24 ₀₃ and 2 are formed by converging one _ends of 4 ₀₂ , 24 ₀₃ and 24 _04.
4 ₀₄ first respectively at the other end, the second, third and fourth exposure unit 20 _01, 20 _02, 20 ₀₃ and 20 ₀₄
Connected to. The illumination light is firstly changed by the optical path changing device 23.
When guided to the end face of the fiber bundle 241, each of the optical fiber cables 24 ₀₁ , 24 ₀₂ , 24 ₀₃ and 24 ₀₄ ,
Illumination light is simultaneously introduced into the first to fourth exposure units ₂₀₀₀₁ , ₂₀₀₀₂ , ₂₀₀₃ and ₂₀₀₄ which are defined as the exposure units of the first group.

The second fiber bundle 242 has four optical fibers.
Cable 24₀₅, 24₀₆, 24₀₇And 24₀₈One end of
It is a bundled optical fiber cable 2
Four₀₅, 24₀₆, 24₀₇And 24₀₈Through the second guru
5th, 6th, 7th defined as exposure units
And the eighth exposure unit 20₀₅, 20₀₆, 20₀₇and
20₀₈Illumination light may be simultaneously introduced to each of the. As well
The four optical fibers forming the third fiber bundle 243
Cable 24₀₉, 24_Ten, 24₁₁And 24₁₂Through
The exposure unit of the third group
9, 10th, 11th and 12th exposure units 20₀₉,
20_Ten, 20₁₁And 20₁₂Illumination light to each of
Of four lights that are introduced into the fourth fiber bundle 244
Fiber cable 24₁₃, 24₁₄, 24₁₅And 24₁₆
Defined as a fourth group of exposure units through
13th, 14th, 15th and 16th exposure units 2
0₁₃, 20 ₁₄, 20₁₅And 20₁₆Illumination light to each of
Will be introduced at the same time.

The optical path changing device 23 distributes the parallel luminous flux emitted from the light source device 22 into four directions. Specifically, the optical paths of the parallel light fluxes are changed toward the end faces of the first fiber bundle 241, the second fiber bundle 242, the third fiber bundle 243, and the fourth fiber bundle 244 in this order.
Therefore, 4 out of ₁₆ exposure units 20 _{01 to} 20 ₁₆
In order, one by one, that is, the first group of exposure units 20 ₀₁ to 2
The illumination light is sequentially supplied to the exposure units 0 ₀₄ , the exposure units 20 _{05 to} 20 _{08 of} the second group, the exposure units 20 _{09 to} 20 _{12 of} the third group, and the exposure units 20 _{13 to} 20 ₁₆ of the fourth group.

FIG. 5 shows exposure units included in each group.
3 is a timing chart showing the exposure timing of the. Dew
Optical clock pulse is one exposure operation for all exposure units
Is a pulse to determine the timing of
From the control circuit 34 to the DMD drive circuit 56 and the read-out
Dress control circuit 58, exposure data memory 54 and optical path
It is output to the changing device 23. Read address control circuit 5
8 shows each exposure in synchronization with the rising edge of the exposure clock pulse.
Start calculation of exposure data to be given to the optical unit, and
It is given to the DMD drive circuit 56 via the optical data memory 54.
It Synchronize with the rising edge of the next exposure clock pulse
1 group of exposure units 20₀₁~ 20 ₀₄, The second glue
Exposure unit 20₀₅~ 20₀₈, Group 3 exposure
Unit 20₀₉~ 20₁₂And the exposure unit of the fourth group
20₁₃~ 20₁₆The exposure operation is performed in this order.

The optical path changing device 23 operates in synchronism with the exposure clock pulse, and the exposure units ₂₀₀₀₁ ...
20 ₀₄ , 20 _{05 to} 20 ₀₈ , 20 _{09 to} 20 ₁₂ and 20 ₁₃
The illumination light is supplied to the first fiber bundle 241 and the second fiber bundle 2 so that the illumination light is supplied when ˜20 ₁₆ performs the exposure operation.
42, third fiber bundle 243 and fourth fiber bundle 24
Sort in order of 4.

[0053] In multi-exposure drawing device 10, and repeated across the exposure of the drawing plane 32 as described above on a number of times, the exposure operation of each exposure unit 20 _{01-20 16} and the calculation of the exposure data exposure clock It is repeated according to the pulse. Therefore, the period T1 of the exposure clock pulse is
It is set to be longer than the time T2 (hereinafter, referred to as data calculation time) required to calculate the exposure data for one exposure operation of all the exposure units 20 _{01 to} 20 ₁₆ . On the other hand, the time T3 required for each exposure unit to perform one exposure operation (hereinafter, referred to as a single exposure time) T3 can be relatively short for one exposure because of multiple exposure. Therefore, it becomes shorter than the exposure cycle T1 and the data calculation time T2.
Therefore, when performing exposure operation of the entire exposure unit 20 _{01-20 16} At the same time, the exposure operation is not performed time (T1-T
3) becomes long and the utilization efficiency of illumination light becomes low.

However, the multiple exposure drawing apparatus 1 of this embodiment
According to 0, the illumination light is distributed sequentially into four groups.
Separate exposure unit 20₀₁~ 20₀₄, 20₀₅~ 20₀₈,
20 ₀₉~ 20₁₂And 20₁₃~ 20₁₆Exposure timing
To improve the utilization efficiency of the illumination light
ing. Also, the total exposure unit 20₀₁~ 20₁₆Illuminate at once
Compared with the case of supplying bright light, the amount of light is about 1/4.
The relationship between the exposure cycle T1 and the single exposure time T3 is expressed by equation (1).
Shown. T1 ≧ T3 × 4 (1)

FIG. 6 is a perspective view conceptually showing the main structure of the optical path changing device 23, and FIG. 7 is a diagram schematically showing the operation of the optical path changing device 23. In FIG. 6 and FIG. 7, the optical path of the illumination light is symbolically shown by a chain line. The optical path changing device 23 includes a circular rotating plate 231 (partially cut away in FIG. 6). A rotary shaft of a motor 239 is integrally attached to the center of the rotary plate 231, and the rotary plate 231 is rotated by the motor 239 at a constant speed. The rotation axis of the rotary plate 231 is π with respect to the parallel light flux incident from the light source device 22.
It is arranged at a position of / 4 [rad].

An origin hole 232 is provided on the outer edge of the rotary plate 231. The origin position detection sensor 234 sends a detection signal to the system control circuit 34, which is normally at a high level and switches to a low level for a predetermined time when the origin hole 232 is detected. System control circuit 34
Monitors the rotation position and rotation cycle of the rotary plate 231 based on the detection result of the origin position detection sensor 234. The motor 239 is rotated by the system control circuit 34 so that the rotary plate 231 synchronizes with the exposure clock pulse and the cycle T4 (T4
Is controlled to rotate at an integer multiple of T1).

The rotary plate 231 transmits or reflects the illumination light depending on its rotation position. For convenience of explanation below,
The surface of the rotating plate 231 on the light flux incident side is defined as a front surface 231a, and the surface on the opposite side is defined as a back surface 231b. A first reflecting mirror 235 (first reflecting member) parallel to the rotating plate 231 is fixedly provided on the surface 231a side of the rotating plate 231. The first reflection mirror 235 transmits the illumination light reflected by the surface 231a of the rotary plate 231 to the surface 231a of the rotary plate 231 again.
Reflect toward. A second reflecting mirror 237 (second reflecting member) parallel to the rotating plate 231 is fixedly provided on the opposite side of the rotating plate 231 from the first reflecting mirror 235. The second reflection mirror 237 reflects the illumination light transmitted through the rotary plate 231 toward the back surface 231b of the rotary plate 231.

The rotating plate 231 is formed of a transparent member into a disk shape having a certain thickness, and a reflecting surface is formed by partially vapor-depositing a metal thin film such as aluminum on the front surface or the back surface thereof. The central angle of the rotating plate 231 is π /
Focusing on the fan-shaped region FR of 2 [rad], the metal thin film is not provided in the first region R1 located at the end and having the center angle of π / 8 [rad]. rad]
In the second region R2 of the metal thin film 23 on a part of the back surface 231b.
11 is provided, and in the third region R3 having the next center angle π / 8 [rad], the metal thin film 231 is formed on a part of the surface 231a.
2 is provided, and in the fourth region R4 having the final central angle π / 8 [rad], the metal thin films 2313 are provided at two positions on the surface 231a.
2314 is provided. In FIG. 6, the metal thin film 2311 provided on the back surface 231b is shown by hatching with broken lines, and the metal thin films 2312, 2313, 2 provided on the front surface 231a are shown.
314 is indicated by solid line hatching.

When the rotary plate 231 is in the first rotation position (FIG. 6) where the illumination light is incident on the first region R1, the light source device 22 is provided.
As shown in FIG. 7 (a), the illumination light incident from is transmitted through the rotating plate 231 and guided to the second reflecting mirror 237, and the second reflecting mirror 237 causes the back surface 231 of the rotating plate 231.
It is reflected toward b, passes through the rotary plate 231 again,
First fiber bundle 241 or four optical fiber cables 2
The end faces of ₄₀₁ , 24 ₀₂ , 24 ₀₃ and 24 ₀₄ are reached.

The rotating plate 231 is rotated counterclockwise by π / 8 [ra].
d] and the illumination light is incident on the second region R2.
When the rotating plate 231 is in the rotating position, as shown in FIG. 7B, the illumination light incident from the light source device 22 passes through the rotating plate 231 and is guided to the second reflecting mirror 237, where
The back surface 231b of the rotating plate 231 is reflected by the reflection mirror 237.
The metal thin film 2 on the rotary plate 231.
It is reflected by 311 and reaches the end face of the second fiber bundle 242, that is, the four optical fiber cables 24 ₀₅ , 24 ₀₆ , 24 ₀₇ and 24 ₀₈ .

Further, the rotary plate 231 is rotated counterclockwise by π / 8.
When the rotary plate 231 is rotated by [rad] and is located at the third rotation position where the illumination light is incident on the third region R3, as shown in FIG.
As shown in (c), the illumination light incident from the light source device 22 is reflected toward the first reflection mirror 235 by the metal thin film 2312 of the rotating plate 231, and the first reflection mirror 23 is reflected.
5 is reflected toward the surface 231a of the rotary plate 231 and further transmitted through the rotary plate 231, and the third fiber bundle 243, that is, the four optical fiber cables 24 ₀₉ , 24 ₁₀ ,
The end faces of 24 ₁₁ and 24 ₁₂ are reached.

Further, the rotary plate 231 is rotated counterclockwise by π / 8.
When the rotation plate 231 is rotated by [rad] and is located at the fourth rotation position where the illumination light is incident on the fourth region R4, as shown in FIG.
As shown in (d), the illumination light incident from the light source device 22 is reflected by the metal thin film 2313 of the rotating plate 231 toward the first reflecting mirror 235, and the first reflecting mirror 23
5 toward the surface 231a of the rotary plate 231 and further reflected by the metal thin film 2314 of the rotary plate 231 to reflect the fourth fiber bundle 244, that is, the four optical fiber cables 24 ₁₃ , 24 ₁₄ , 24 ₁₅ and 24 ₁₆ . Reach the end face.

In the present embodiment, the angle formed by the rotation axis of the rotary plate 231 and the parallel light flux incident from the light source device 22 is set to π / 4 [rad], and the first and second reflection mirrors 235 and 237 is parallel to the rotary plate 231, but the relative positional relationship between them is not particularly limited to this embodiment, and the angle formed by the rotation axis and the parallel light flux is π / 4 [rad].
The first and second reflection mirrors 235 and 237 do not have to be parallel to the rotary plate 231, and
It suffices that the second reflection mirrors 235 and 237 be positions that can reflect incident light to different positions in the radial direction of the rotary plate 231.

FIG. 8 is a plan view of the rotary plate 231 viewed from the front surface 231a side. The first region R1 has a central angle α (= π /
8 [rad]) and the first region R1 is not provided with a metal thin film, so two fan-shaped transmission regions arranged on the same circumference, that is, the outer radius is r1 and the inner radius is The first transmissive area AR that is r2 and has a central angle α
1 (enclosed by a broken line in the figure), the second transmission region AR2 is arranged closer to the rotation axis than the first transmission region AR1, that is, the outer radius is r2, the inner radius is r3, and the central angle α is present.
(Enclosed by a broken line in the figure). When the rotary plate 231 is in the first rotation position shown in FIG. 6, the illumination light is incident on the first transmissive area AR1 from the front surface 231a side, is transmitted through the first transmissive area AR1, is reflected by the second reflection mirror 237, and is reflected by the second transmissive area. AR2 is transmitted from the back surface 231b side.

The second region R2 has a third transmission region AR3 that transmits the illumination light and guides it to the second reflection mirror 237, and a first reflection region BR1 that further reflects the reflection light from the second reflection mirror 237. Then it can be considered. The third transmissive area AR3 is a fan-shaped area (enclosed by a broken line in the drawing) having an outer radius r1 and an inner radius r2 and a central angle α.
The first reflection region BR1 is a fan-shaped region (indicated by a dashed line in the drawing) on the rotation axis side of the first reflection region BR1, that is, the outer radius is r2 and the inner radius is r3, and the central angle is α.

The third region R3 includes a second reflection region BR2 that reflects the illumination light and guides it to the first reflection mirror 235, and a fourth transmission region AR that transmits the reflection light from the first reflection mirror 235.
4 and can be considered to have. Second reflection area BR
2 is on the same circumference as the first transmission region AR1 and the third transmission region AR3, that is, the outer radius is r1 and the inner radius is r2.
Is a fan-shaped region with a central angle α (indicated by solid line hatching in the figure), and the fourth transmission region AR4 is closer to the rotation axis than the second reflection region BR2, that is, the outer radius is r3 and the inner radius is r4. And is a fan-shaped region having a central angle α (enclosed by a broken line in the figure).

The fourth region R4 has a third reflection region BR3 that reflects the illumination light and guides it to the first reflection mirror 235, and a fourth reflection region BR4 that further reflects the reflection light from the first reflection mirror 235. Then it can be considered. The third reflective area BR3 is composed of the first transmissive area AR1 and the third transmissive area AR.
3 and the second reflection region BR2 on the same circumference, that is, the outer radius is r1 and the inner radius is r2, and the sector region has a central angle α (indicated by solid line hatching in the figure),
The fourth reflection region BR4 is a fan-shaped region (shown by solid line hatching in the figure) closer to the rotation axis than the third reflection region BR3, that is, having an outer radius r3 and an inner radius r4 and a central angle α.

As described above, the fan-shaped region FR includes the first region R including the first transmission region AR1 and the second transmission region AR2.
1, a second region R2 including a third transmissive region AR3 and a first reflective region BR1, a second reflective region BR2 and a fourth region R2.
A third region R3 having a transmissive region AR4 and a fourth region R4 having a third reflective region BR3 and a fourth reflective region BR4.
Composed of and. In the first region R1, the second transmission region AR2 is provided on the rotation axis side, that is, on the radially inner side of the first transmission region AR1, but the first transmission region AR1 may be on the radially inner side. At this time, the incident position of the illumination light may be changed. The same applies to the other regions R3 to R4, and the arrangement of the first and second reflection mirrors 235 and 237, the inclination with respect to the rotation axis, the incident position of the illumination light, and the direction thereof can be appropriately changed.

The rotary plate 231 is used in this embodiment.
Are formed of a transparent material, and the first to fourth reflective regions BR1 to BR are formed.
Although R4 is formed by aluminum vapor deposition, the structure is not particularly limited to this. For example, the rotating plate 231 is formed of a material having a high reflectance, and the first to fourth transmission regions AR1 to AR are formed.
You may form a fan-shaped hole by cutting the part corresponding to 4.

Also, the radii r1, r2, r3, and r4
The value of is not particularly limited, but satisfies the condition of r1>r2>r3> r4 and is the radial length of the transmissive regions AR1 to AR4 or the reflective regions BR1 to BR4 (r1-r
2), (r2-r3) and (r3-r4) may be long enough to allow illumination light to pass therethrough.

The structure of the fan-shaped region FR is also applied to the remaining 3π / 2 [rad] region of the rotary plate 231.
The first region R1 to the fourth region R4 are sequentially provided at four places on the entire circumference of the No. 1 in order. Therefore, the rotary plate 231
Is π / 2 [r in the counterclockwise direction when viewed from the surface 231a side.
ad], the first fiber bundle 241, the second fiber bundle 242, the third fiber bundle 243, and the fourth fiber bundle 244 are sequentially supplied with illumination light for a fixed time respectively, and when the rotating plate 231 makes one rotation, That is, the distribution of the illumination light is repeated four times.

The illumination light is supplied to each of the fiber bundles 241, 242, 243 and 244 in a single exposure time T.
3 is set to substantially match. In other words, the rotation cycle T4 of the rotary plate 231 is set to four times the exposure cycle T1. As a result, the central angle α (= π / 8 [ra
d]) the time required for each of the regions R1 to R4 to cross the optical path, that is, each fiber bundle 241, 242, 243 and 2
The supply time of the illumination light to 44 corresponds to the single exposure time T3.

In the present embodiment, the central angle α of each of the regions R1 to R4 is set to π / 8 [rad] and the rotation cycle T4 of the rotary plate 231 is set to T1 × 4, but it is particularly limited to these values. However, it suffices if the following expression (2) is satisfied, and that the central angles of all the regions R1 to R4 are equal values. For example, when the central angle α is set to double (π / 4 [rad]), the rotation cycle is set to 1/2, that is, the rotary plate 231 is set to two.
Rotate at double speed. T3 / T4 = α / 2π (2)

[0074] As described above, multi-exposure drawing device 10 of the present embodiment, each distributes the illumination light 16 of the exposure unit 20 _{01-20 16} according to the rotation plate 231 in its rotational position by constant speed The optical path changing device 23 is provided so that the illumination light is used 100%, that is, the utilization efficiency of the light source device 22 is improved. In the optical path changing device 23, since the motor 239 only needs to rotate the rotary plate 231 at a constant speed, the assembly and drive control circuit can be simply configured, and the cost is low and the failure is unlikely to occur. In addition, the rotary plate 231 is formed of a transparent material, and an aluminum thin film is vapor-deposited on a part of the rotary plate 231 to form a transmissive region and a reflective region.
The rotary plate 231 can be obtained by a relatively simple operation.

[0075]

As described above, in the multiple-exposure drawing apparatus 10 of the present invention, the light path changing device 23 distributes the illumination light to the plurality of exposure units 20 _{01 to} 20 ₁₆ , so that the utilization efficiency of the illumination light is improved. There are advantages.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a multiple exposure drawing apparatus according to the present invention.

FIG. 2 is a schematic conceptual diagram for explaining a function of an exposure unit used in the multiple exposure drawing apparatus according to the present invention.

FIG. 3 is a block diagram of a multiple exposure drawing apparatus according to the present invention.

FIG. 4 is a top view of the gate-like structure of the multiple-exposure drawing apparatus shown in FIG. 1, showing a simplified connection relationship between the optical path changing device, the optical fiber cable, and the exposure unit.

FIG. 5 is a timing chart showing the exposure timing of the exposure unit divided into four groups.

FIG. 6 is a perspective view conceptually showing the main structure of the optical path changing device shown in FIG.

FIG. 7 is a diagram schematically showing the operation of the optical path changing device shown in FIG.

FIG. 8 is a plan view of a part of a rotary plate as seen from an illumination light incident side.

[Explanation of symbols]

10 Multiple exposure drawing device 20 ₀₁ , ... 20 ₁₆ Exposure unit 22 Light source device 23 Optical path changing device (optical path changing means) M (1,1), ... M (1024,1280) Micro mirror (modulating element) 32 Drawing surface 34 system Control circuit 231 Rotating plate 235 First reflection mirror 237 Second reflection mirror

Claims (10)

[Claims] 1. A multiple exposure apparatus for drawing a predetermined circuit pattern by performing multiple exposure using a plurality of exposure units having a large number of modulation elements arranged in a matrix, wherein illumination light of a constant intensity is continuously emitted. A multiple-exposure drawing apparatus comprising: an optical path changing unit that is provided between a light source that selectively emits light and the exposure unit and that selectively distributes the illumination light to each of the exposure units. 2. The optical path changing means includes a rotating plate member that rotates about a predetermined rotation axis and reflects or transmits the illumination light according to the rotation position. Multiple exposure drawing device. 3. The multiple exposure drawing according to claim 2, wherein the exposure unit repeatedly performs an exposure operation at a predetermined exposure cycle, and the rotation cycle of the rotary plate member is an integral multiple of the exposure cycle. apparatus. 4. The rotating plate member is made of a transparent material, and a reflection region for reflecting the illumination light is formed by depositing aluminum on one surface of the rotating plate member. 2. The multiple exposure drawing apparatus according to item 2. 5. An area different from the reflection area in the radial direction of the rotation plate member, the irradiation light reflected by a predetermined reflection area of the rotation plate member being perpendicular to the rotation axis of the rotation plate member. A first reflecting member that reflects toward the illumination light, and illumination light that has passed through a predetermined transmission region of the rotating plate member,
The multiple-exposure drawing apparatus according to claim 2, further comprising a second reflecting member that reflects toward a region different from the transmissive region in the radial direction of the rotary plate member. 6. The first reflecting member is fixed to the rotary plate member on the incident side of the illumination light, and the second reflecting member is fixed to the rotary plate member on the opposite side of the first reflecting member. The multiple-exposure drawing apparatus according to claim 5, wherein: 7. The rotation axis of the rotary plate member is on a plane including the incident optical axis of the illumination light and is inclined by π / 4 [rad] with respect to the incident optical axis, The multiple-exposure drawing apparatus according to claim 5, wherein the reflecting surfaces of the first and second reflecting members are parallel to a radial direction perpendicular to the rotation axis. 8. The rotating plate member includes a first transmissive region that transmits the illumination light incident from the light source and guides it to the second reflecting member when the rotating plate member is in the first rotation position. When the rotary plate member is in the first rotation position, the illumination light which is arranged on the rotation axis side with respect to the first transmission region, passes through the first transmission region, and is reflected by the second reflection member. A second transmissive region which is further transmitted and is guided to the exposure unit of the first group; and a second transmissive region which is arranged on the same circumference as the first transmissive region when the rotary plate member is in the second rotational position and which is incident from the light source A third transmissive region that transmits the illuminated light and guides it to the second reflecting member; and a third transmissive region that is arranged on the rotation axis side of the third transmissive region when the rotary plate member is in the second rotational position. 3 through the transmission area and is reflected by the second reflecting member. A first reflection region that further reflects the illumination light and guides it to the exposure unit of the second group, and is arranged on the same circumference as the first transmission region when the rotating plate member is in the third rotation position, A second reflection area that reflects the illumination light incident from the light source toward the first reflection member; and a second reflection area closer to the rotation axis than the second reflection area when the rotary plate member is in the third rotation position. A fourth transmission region, which is disposed and guides the illumination light reflected by the second reflection region and the first reflection member to the exposure unit of the third group, and the rotary plate member is at the fourth rotation position. Sometimes a third reflection region, which is arranged on the same circumference as the second reflection region and reflects the illumination light incident from the light source toward the first reflection member, and the rotary plate member is at the fourth rotation position. Than the third reflection area when A fourth reflection region, which is disposed on the rotation axis side and further guides the illumination light reflected by the third reflection region and the first reflection member to the exposure unit of the fourth group, is provided. Claim 3
The multiple-exposure drawing apparatus according to item 1. 9. The rotary plate member comprises the first, second and third rotary plate members.
9. The multiple exposure drawing apparatus according to claim 8, wherein the time kept in the fourth rotation position substantially corresponds to the time required for one exposure operation of the exposure unit. 10. An illumination mechanism provided in a multiple exposure apparatus for drawing a predetermined circuit pattern by performing multiple exposure using a plurality of exposure units having a large number of modulation elements arranged in a matrix, and having a constant intensity. Of a multiple-exposure drawing apparatus, which is provided between a light source that continuously emits the illumination light and the exposure unit, and includes an optical path changing unit that selectively distributes the illumination light to each of the exposure units. Lighting mechanism.