JP2004054101A - Laser direct plotting device having automatic resolution setting function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser direct plotting device by which operator-working processes for and labor costs are reduced and a short appointed date of delivery for products and parts and cost reduction are achieved by allowing automatic switching of resolution, particularly, the resolution of a plotting surface in the sub-scanning direction. <P>SOLUTION: The laser direct plotting device plots a desired pattern on the plotting surface by moving the plotting surface in the sub-scanning direction with a beam deflecting to the plotting surface in the main scanning direction. Where, the laser direct plotting device comprises: a resolution setting means setting the resolution; a monitor means monitoring the resolution on the plotting surface; and a control means controlling the resolution setting means by referring to a monitor result by the monitor means. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a laser direct drawing apparatus that draws a desired pattern on a drawing surface by moving the drawing surface in a sub-scanning direction while deflecting a laser beam in the main scanning direction with respect to the drawing surface.
[0002]
[Prior art]
A main application of the laser writing apparatus is to form a circuit pattern by exposing a photoresist layer on a substrate to a laser beam. As a drawing method, there is a method of drawing a desired pattern on the drawing surface by moving the drawing surface in the sub-scanning direction while deflecting the laser beam in the main scanning direction with respect to the drawing surface. Compared with a mask exposure apparatus that performs exposure using a mask, this laser drawing apparatus has advantages such as processlessness and running cost reduction because a mask is not required, and has been widely used in recent years.
[0003]
In recent years, as demands for shorter delivery time and cost reduction of products and parts, etc., have increased, there has been a demand for faster production lines and automation. For speeding up the production line, it is configured to draw patterns on the drawing surface with multiple beams, speeding up the exposure process, and for automating the manufacturing line, it is possible to cooperate with external equipment such as automatic substrate supply equipment Some have been automated.
[0004]
[Problems to be solved by the invention]
However, the above-described laser drawing apparatus has various steps that require the work of the operator, and for example, the resolution, particularly the resolution in the sub-scanning direction with respect to the drawing surface, is manually adjusted by the operator to change the setting. And set the resolution. For this reason, even if the speed of the exposure processing is increased by using the multi-beam, the above-mentioned manual operation or the like takes time, and it is difficult to achieve the speeding up of the manufacturing line. In addition, labor costs are incurred due to this work, and it is difficult to achieve cost reduction.
[0005]
In view of the above circumstances, the present invention makes it possible to reduce the number of steps and labor costs for an operator by enabling automatic switching of resolution, particularly resolution in the sub-scanning direction with respect to a drawing surface, in a laser drawing apparatus. It is another object of the present invention to provide a laser direct writing apparatus capable of shortening the delivery time and cost of products and parts.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the laser direct writing apparatus according to claim 1 deflects a beam in the main scanning direction with respect to the drawing surface, moves the drawing surface in the sub-scanning direction, and moves the drawing surface onto the drawing surface. In a laser direct-writing apparatus that draws a desired pattern, the laser direct-writing apparatus includes a resolution setting unit that sets a resolution, a monitor unit that monitors a resolution on a drawing surface, and a resolution setting unit based on a monitoring result by the monitor unit. And control means for controlling. When the laser direct writing apparatus is configured in this manner, the resolution can be automatically switched, so that the steps and labor costs for the operator can be reduced, so that the delivery time of products and parts can be shortened and the cost can be reduced.
[0007]
Further, in the laser direct-writing apparatus according to claim 2, the resolution setting means has an input section that allows an operator to set a desired resolution, and the control means sets the resolution in accordance with the resolution input to the input section. The setting means is controlled. By configuring the laser direct writing apparatus in this way, the operator can set the resolution simply by inputting it to a workstation or the like, so that the switching of the resolution can be automated, and the number of steps and labor costs for the operator can be reduced. Shorter delivery time and cost reduction of parts can be achieved.
[0008]
Further, the laser direct writing apparatus according to claim 3 has an optical system for guiding a beam onto a drawing surface, and the resolution setting means includes a driving means for rotating and driving a part of the optical system about the optical axis. Beam splitting means for splitting the book beam into a plurality of beams arranged in a line, and rotating a part of the optical system around the optical axis to change the inclination of the plurality of beams arranged in a line In this case, the resolution is set. When a part of the optical system is driven to rotate around the optical axis and the beam train is rotated with the rotation of the optical system, the configuration can be simplified, and the size and cost can be reduced. .
[0009]
A laser direct writing apparatus according to a fourth aspect of the present invention is characterized in that the laser direct writing apparatus has a rotating unit for rotating the passing light beam around the optical axis, and a part of the optical system is a rotating unit. By configuring the laser direct writing apparatus in this manner, in switching the resolution, it is possible to use a rotating unit having no limitation on the rotation angle, so that any resolution can be set.
[0010]
The laser direct writing apparatus according to claim 5 is characterized in that a part of the optical system is a beam splitting unit. By configuring the laser direct writing apparatus in this manner, the beam splitting means can be used for switching the resolution, so that the configuration can be simplified, and the size and cost can be reduced.
[0011]
Further, the laser direct writing apparatus according to claim 6 has a rotation unit for rotating the passing light beam around the optical axis, and a part of the optical system is a rotation unit and a beam splitting unit. And As described above, by adopting a hybrid system in which both the rotating unit and the beam splitting unit are used for switching the resolution of the laser direct writing apparatus, higher resolution can be achieved.
[0012]
Further, in the laser direct-writing apparatus according to claim 7, the monitor means has a solid-state imaging device disposed at a position conjugate with the drawing surface. By configuring the laser direct writing apparatus in this way, the beam position can be detected by image processing.
[0013]
Further, in the laser direct writing apparatus according to claim 8, the monitor means monitors the interval in the sub-scanning direction between the beams at both ends of the plurality of beams arranged in a line and received by the solid-state imaging device. . By configuring the laser direct writing apparatus in this way, the control unit can perform stable control in automatic switching of resolution.
[0014]
Further, the direct laser writing apparatus according to the ninth aspect has a drawing table for moving the drawing surface in the sub-scanning direction, and the control means controls the moving speed of the drawing table in the sub-scanning direction according to the set resolution. Is changed. By configuring the laser direct writing apparatus in this manner, the resolution of the beam scanned on the drawing surface can be always kept constant.
[0015]
The laser direct writing apparatus according to claim 10, further comprising a polygon mirror that deflects the beam with respect to the drawing surface and scans the beam by rotating the beam in the main scanning direction. The number of rotations of the polygon mirror is changed in accordance with By configuring the laser direct writing apparatus in this manner, the resolution of the beam scanned on the drawing surface can be always kept constant.
[0016]
Further, in the laser direct writing apparatus according to the eleventh aspect, the laser direct writing apparatus has a beam adjusting unit for adjusting a beam output, and the control unit controls the beam adjusting unit in accordance with the set resolution. It is characterized by doing. By configuring the laser direct drawing apparatus in this manner, the exposure energy of the beam scanned on the drawing surface can be always kept constant.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a perspective view showing a schematic configuration of a laser direct-writing apparatus 100 according to an embodiment of the present invention. The laser direct writing apparatus 100 has a base 10 installed on a floor surface, and is configured by components installed on the base 10. A pair of rails 20 are provided on the base 10. An X table 21 is provided on the pair of rails 20. Further, a θ table 22 is provided on the X table 21, and a drawing table 23 is provided on the θ table 22. On the drawing table 23, a plurality of substrates 200 each having a photoresist layer on which a circuit pattern is drawn by the laser direct drawing apparatus 100 are transported by an external device and arranged on the drawing table 23.
[0018]
The X table 21 is connected to a stepping motor 21a (not shown), and is moved by the motor on the pair of rails 20 in the sub-scanning direction (the direction of the double arrow in FIG. 1). In addition, with the movement of the X table 21, the θ table 22 and the drawing table 23 are also moved in the sub-scanning direction.
[0019]
The fixed table 30 is provided on the base 10. An optical system 50 to be described later is provided in the fixed table 30. The optical system 50 scans the drawing table 23 in a direction substantially parallel to the main scanning direction (Y direction) of the drawing table 23. Is irradiated. At this time, the drawing table 23 moves in the sub-scanning direction described above, and the substrate 200 moves with the movement. The substrate 200 moves in the sub-scanning direction (X direction) with respect to the optical system 50 while the scanning beam is irradiated substantially parallel to the main scanning direction. The entire desired circuit pattern is drawn.
[0020]
FIG. 2 is a diagram illustrating a configuration of the optical system 50 according to the first embodiment of the present invention. The optical system 50 includes an argon laser oscillator 51, a DBS (Diffractive Beam Separator) 52, a collimating lens 53, an acousto-optic element 54, a rotator 55, a polygon mirror 56, and an fθ lens 57.
[0021]
The argon laser oscillator 51 is a water-cooled type, has an output of 1.8 W, and oscillates a laser having a wavelength of 488 nm. The beam oscillated by the argon laser oscillator 51 is incident on the DBS 52.
[0022]
The DBS 52 is a transmissive grating-type light beam splitting element made of a transparent resin material or a glass material and diffracting incident light to split the light into a plurality of light beams. The DBS 52 can split incident light with high diffraction efficiency. In the embodiment of the present invention, a beam incident on the DBS 52 is split into 17 rows of light beams. However, since even-numbered light beams are easier to handle as data, one of the higher-order light beams is not used in the embodiment of the present invention. Therefore, 16 light beams are actually used. The light beam split by the DBS 52 is incident on the collimator lens 53 as 16 light beams. The figure shows only a part of the light beam.
[0023]
The collimator lens 53 converts the 16 light beams emitted from the DBS 52 into parallel light. The 16 light beams converted into the parallel light enter the acousto-optic device 54.
[0024]
The acousto-optic element 54 is an element utilizing the occurrence of an acousto-optic effect in all optical media when a beam and an acoustic wave are present in a predetermined medium. The acousto-optic element 54 emits 16 light beams emitted from the collimator lens 53. Diffract according to the presence or absence of generation of ultrasonic waves. The CPU 80 controls whether or not ultrasonic waves are generated. The CPU 80 performs control based on pattern drawing data given by the operator. In the acousto-optic device 54, the beam for drawing is diffracted, and the beam for not drawing is not diffracted. Each light beam diffracted by the acousto-optic device 54 is guided to the rotator 55. Each light beam that is not diffracted by the acousto-optic device 54 is transmitted through the acousto-optic device 54 and then absorbed by the inner wall of the fixed table 30 or a light shielding plate.
[0025]
The rotator 55 is an optical element having a trapezoidal prism and a plane-parallel plate, and is configured to rotate about the optical axis by driving a stepping motor 70. Each light beam emitted from the acousto-optic device 54 is arranged in a row. When the rotator 55 is driven to rotate about the optical axis, the inclination of the beam train changes as the rotator 55 rotates. The rotation of the rotator 55 is performed under the control of a CPU 80 described later. The beam train rotated by the rotator 55 is guided to the polygon mirror 56.
[0026]
The polygon mirror 56 is provided with six reflecting surfaces around the rotation axis so that the respective reflection surfaces are located at the same distance from the rotation center, and is driven to rotate counterclockwise in the figure around the rotation axis by a motor (not shown). . The beam train emitted from the rotator 55 is irradiated toward the rotation center of the polygon mirror 56, and is reflected and deflected by these reflecting surfaces. The reflected and deflected beam train enters the fθ lens 57. The resolution of the drawing pattern in the main scanning direction is determined by the rotation speed of the polygon mirror 56 and the timing of the modulation by the acousto-optic device 54.
[0027]
lens 57 is an element for keeping the scanning speed in the main scanning direction of the beam train reflected and deflected by the polygon mirror 56 constant. The beam train is converged by the fθ lens 57 and guided to the drawing table 23 via a mirror or lens (not shown). Then, 16 scanning lines are simultaneously formed on the plurality of substrates 200 arranged on the drawing table 23 by the beam train, and a desired circuit pattern 200a is drawn.
[0028]
FIG. 3 is a diagram showing a positional relationship between the drawing table 23 and the CCD 60. As shown in FIG. 3, the CCD 60 is fixedly supported on the side of the drawing table 23 in the main scanning direction such that the light receiving surface 60a of the CCD 60 and the drawing plane of the drawing table 23 have the same height. This means that both are arranged at conjugate positions with respect to the optical system 50. The CCD 60 is used as a CCD for detecting a beam interval for detecting a scanning interval of the beam train guided to the drawing table 23 by a detection method described later.
[0029]
FIG. 4 is a diagram showing a beam arrangement at a writing position. The beam train projected on the drawing table 23 is not parallel to the main scanning direction (Y direction) and has a slight inclination D. When the inclination D is increased or decreased, the beam interval Δd in the sub-scanning direction (that is, the scanning line interval) changes. That is, the resolution in the sub-scanning direction changes according to the increase or decrease of the inclination D. The rotation center of the inclination D is made to coincide with the optical axis beam 150. In addition, optical adjustment is performed so that the rotation axis of the rotator 55 and the optical axis beam 150 also coincide. By performing the optical adjustment in this manner, the inclination D of the beam train on the drawing table 23 and the rotation angle of the rotator 55 have an equivalent relationship. At this time, since the length in the direction of the sub-scanning area drawn by the 16 scanning lines changes, the moving speed of the drawing table 23 in the sub-scanning direction is changed accordingly. Hereinafter, the moving speed of the drawing table 23 in the sub-scanning direction will be described.
[0030]
FIG. 3 shows a drawing pattern 210 drawn by 16 scanning lines scanned first, and a drawing pattern 220 drawn by 16 scanning lines scanned next to the drawing pattern 210. The beam spacing for each scanning line of a line drawing pattern 210 and d _1. Further, a drawing pattern 210, the beam interval between the drawing pattern 220, i.e. the closest scan line drawing pattern 220 in the drawing pattern 210, the beam interval between the closest scan line to drawing pattern 210 in the drawing pattern 220 and _{d 2} I do. Since the resolution must always be constant on the drawing surface, the CPU 80 sets the drawing table 23 in the sub-scanning direction so that d ₁ and d ₂ are equal no matter what resolution is set. Set the moving speed. That is, the speed of the drawing table 23 is set such that the drawing table 23 moves by a distance of 16 × d _{1 in} the sub-scanning direction from the start of the scanning of the drawing pattern 210 to the start of the scanning of the drawing pattern 220.
[0031]
FIG. 5 is a flowchart for setting the resolution in the sub-scanning direction according to the embodiment of the present invention. The description of this flowchart is shown below. First, an operator operates a workstation or the like to set a drawing resolution of a circuit pattern drawn on the substrate 200 (S1). The CPU 80 reads data corresponding to this resolution from a data table (not shown) of the CPU 80, and sets the moving speed of the drawing table 23 in the sub-scanning direction according to the set resolution (S2). The rotator 55 rotates clockwise or counterclockwise about the optical axis (S3). Due to this rotation, the inclination D of the beam train on the drawing table 23 changes, and the beam interval Δd in the sub-scanning direction also changes. The beam interval Δd is detected by the CCD 60. When the detection result Δd becomes a value that falls within the tolerance of the set resolution, the processing is terminated. If the detection result Δd is a value outside the set resolution tolerance, the rotator 55 is rotated again (S4). The CPU 80 repeats a closed loop for rotating the rotator 55 until the beam interval Δd reaches the level of the set resolution.
[0032]
In the embodiment of the present invention, the resolution that can be set is 2.5, 5.0, 10.0 μm. However, when the rotator 55 is used to change the resolution as in this embodiment, the rotator 55 has no restriction on the rotation angle, so that a higher resolution can be set.
[0033]
Next, a detection method for detecting the scanning interval of the beam train using the CCD 60 will be described. As described above, the light receiving surface 60a of the CCD 60 and the drawing plane of the drawing table 23 are disposed at optically equivalent positions, and the light receiving surface 60a scans only the beams at both ends of a beam train having n beams. Let it. Then, the interval between the obtained line images between the two beams is measured by the image processing device, and the beam interval Δd is calculated from the obtained value. In the case of this measurement method, since the intervals between the beams at both ends are measured, a value in which the intervals between the beams are averaged can be calculated, and stable determination can be performed. FIG. 6 is a diagram showing an image of the CCD 60 when only the beams at both ends are scanned. The inside of the circle is the field of view of the CCD, and the hatched lines are line images of the scanning light of the beams at both ends.
[0034]
FIG. 7 is a diagram illustrating a configuration of an optical system 50a according to the second embodiment of the present invention. In the optical system 50a, the same components as those of the optical system 50 of the first embodiment shown in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, the resolution is changed by rotating the DBS 52 instead of the rotator.
[0035]
The DBS 52 is configured to rotate around the optical axis by driving the stepping motor 70a, and is optically adjusted so that the rotation axis and the optical axis beam 150 shown in FIG. 4 coincide. By performing the optical adjustment in this manner, the inclination D of the beam train on the drawing table 23 and the rotation angle of the DBS 52 have an equivalent relationship. The stepping motor 70a is controlled by the CPU 80 in the same manner as the stepping motor 70 of the first embodiment.
[0036]
The acousto-optic element 54 has 16 channels. Each channel has an arrangement and an interval equivalent to the beam train generated by the DBS 52. Each channel has a diffraction effective range for diffracting each beam, and this diffraction effective range is configured to be larger than each beam diameter. When the DBS 52 rotates, each beam is shifted by the rotation and enters each channel. At this time, if the beam incident on each channel goes out of the effective diffraction range, diffraction loss occurs, and it becomes impossible to draw an accurate circuit pattern 200a due to insufficient light quantity. Therefore, the range of the rotation angle of the DBS 52 is such that each beam does not go out of the diffraction effective range.
[0037]
In the second embodiment of the present invention, the number of components is reduced by using the DBS 52 for changing the resolution. Therefore, in this embodiment, size reduction and cost reduction can be achieved.
[0038]
The above is the embodiment of the present invention. The present invention is not limited to these embodiments, and can be modified in various ranges.
[0039]
In the above embodiment, the resolution is changed by rotating either the rotator 55 or the DBS 52. However, the resolution may be changed by rotating both the rotator 55 and the DBS 52. In this case, it is possible to achieve a high resolution that cannot be realized in the above embodiment. For example, the difference is utilized by shifting the phase of the stop angle between the stepping motor 70 that drives the rotator 55 and the stepping motor 70a that drives the DBS 52, or changing the step angle of each stepping motor to a different angle. Thus, high resolution can be obtained.
[0040]
In the above embodiment, the moving speed of the drawing table 23 in the sub-scanning direction is set according to the resolution set by the operator, but the rotation speed of the polygon mirror 56 is set according to the set resolution. Is also good. Since the polygon mirror 56 is lighter in weight than the drawing table 23, the load on the motor is small. Therefore, it is better to increase the rotation speed of the polygon mirror 56 and increase the rotation speed of the polygon mirror 56 than to increase the rotation speed of the stepping motor 21a and increase the movement speed of the drawing table 23. As a result, it is possible to reduce the size and cost of a driving mechanism such as a motor. Further, the light source output of the argon laser oscillator 51 may be set according to the set resolution. Further, the sensitivity of the resist material may be selected according to the setting of the resolution. In this case, the material of the resist material on which the drawing pattern is drawn may be selected according to the setting of the resolution, and the motor and the light source do not need to be changed according to the setting of the resolution.
[0041]
【The invention's effect】
As described above, the laser direct writing apparatus of the present invention drives a part of the optical system to rotate around the optical axis, monitors the beam interval on the drawing surface that rotates with the rotation of the optical system, and drives the driving unit. It was configured to control. For this reason, the process of switching the resolution is automated, the process of the operator and the labor cost can be reduced, and it is possible to shorten the delivery time and cost of products and parts.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating a schematic configuration of a laser direct-writing apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration of an optical system according to the first embodiment of the present invention.
FIG. 3 is a diagram illustrating a positional relationship between a drawing table and a CCD according to the embodiment of the present invention.
FIG. 4 is a diagram showing a beam arrangement at a writing position according to the embodiment of the present invention.
FIG. 5 is a flowchart for setting the resolution in the sub-scanning direction according to the embodiment of the present invention.
FIG. 6 is an explanatory diagram of a beam interval detecting method using a beam interval detecting CCD according to the embodiment of the present invention.
FIG. 7 is a diagram illustrating a configuration of an optical system according to a second embodiment of the present invention.
[Explanation of symbols]
10 base 50 fixed table 52 DBS
55 Rotator 60 CCD
80 CPU

Claims (11)

While deflecting the beam in the main scanning direction with respect to the drawing surface, moving the drawing surface in the sub-scanning direction, a laser direct drawing apparatus that draws a desired pattern on the drawing surface,
The laser direct-writing apparatus, resolution setting means for setting the resolution,
Monitoring means for monitoring the resolution on the drawing surface;
Control means for controlling the resolution setting means based on the result of monitoring by the monitoring means. The resolution setting means has an input unit that allows an operator to set a desired resolution,
2. The laser direct writing apparatus according to claim 1, wherein the control unit controls the resolution setting unit according to a resolution input to the input unit. The laser direct writing apparatus has an optical system for guiding the beam on the drawing surface,
The resolution setting means, a driving means for driving a part of the optical system to rotate about the optical axis,
Beam splitting means for splitting one beam into a plurality of beams arranged in a row,
3. The resolution is set by rotating a part of the optical system around an optical axis to change the inclination of the plurality of beams arranged in a line. A laser direct-writing apparatus according to any one of the above. The laser direct writing apparatus has a rotating unit that rotates the passing light beam around the optical axis,
The laser direct writing apparatus according to claim 3, wherein a part of the optical system is the rotating unit. The laser direct writing apparatus according to claim 3, wherein a part of the optical system is the beam splitting unit. The laser direct writing apparatus has a rotating unit that rotates the passing light beam around the optical axis,
Part of the optical system, the rotating means,
The laser direct writing apparatus according to claim 3, wherein the beam splitting means is provided. The laser direct writing apparatus according to claim 1, wherein the monitor has a solid-state imaging device disposed at a position conjugate with the drawing surface. 8. The laser direct writing apparatus according to claim 7, wherein the monitor monitors an interval in a sub-scanning direction between beams at both ends of the plurality of beams arranged in a line received by the solid-state imaging device. . The laser direct writing apparatus has a drawing table for moving the drawing surface in the sub-scanning direction,
The laser direct writing apparatus according to any one of claims 1 to 8, wherein the control unit changes a moving speed of the drawing table in the sub-scanning direction according to a set resolution. The laser direct-writing apparatus has a polygon mirror that deflects the beam with respect to the drawing surface and scans the beam in the main scanning direction by rotating.
9. The laser direct writing apparatus according to claim 1, wherein the control unit changes the rotation speed of the polygon mirror according to a set resolution. The laser direct writing apparatus has a beam adjusting means for adjusting the output of the beam,
The laser direct writing apparatus according to any one of claims 1 to 8, wherein the control unit controls the beam adjusting unit according to a set resolution.

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