JPH10162145A - Arithmetic unit for calculating correction data of center coordinate data of registered pattern in pattern matching method, and laser plotting device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately and easily obtain center coordinate data of a registered pattern in a pattern matching method by finding the center coordinate data of the registered pattern by an image processing circuit. SOLUTION: A specific pattern, which is similar to a positioning mark, is selected by using a mouse 108 to generate a registered pattern. Then, the positioning mark on a substrate is photographed by a CCD camera 78 and its image-processed positioning mark pattern is matched against the registered pattern to find tentative center coordinate data of the registered pattern. Then the registered pattern is rotated by a half round, 180 deg., around a registration window and registered as a registered half-turn pattern, and pattern matching is carried out to find tentative center coordinate data of the registered half-turn pattern. On the basis of the tentative center coordinate data of the registered pattern and registered half-turn pattern, data on the quantity of deviation of the registered pattern from the center of the registration window is found.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an arithmetic unit for calculating correction data of center coordinate data of a registered pattern in a pattern matching method, and a laser writing apparatus using the same.

[0002]

2. Description of the Related Art A laser drawing apparatus as described above performs a drawing operation by moving a drawing object in a sub-scanning direction while deflecting a laser beam in a main scanning direction with respect to the drawing object. Generally, it is used for drawing a fine pattern on the surface of an appropriate object by using a laser beam. A typical example of the use is to draw a circuit pattern when manufacturing a printed circuit board using a photolithographic technique, and the object to be drawn is, for example, a photosensitive film for a photomask or a photoresist layer on the substrate. And so on.

In recent years, a series of processes from the process of designing a circuit pattern to the process of drawing the circuit pattern have been integrated, and the laser writing apparatus plays a part in such an integrated system. In addition, such an integrated system includes a CAD (Compu
ter Aided Design) station, a CAM (Computer Aided Manufacturing) that edits the circuit pattern data obtained by the CAD station, that is, vector data.
Stations and the like are provided.

[0004] Vector data created by a CAD station or vector data edited by a CAM station is transferred to a laser drawing apparatus, where the vector data is converted into raster data. In a laser writing apparatus, an object to be drawn such as a photosensitive film for a photomask or a photoresist layer on a substrate is scanned by a laser beam and sequentially moved in a sub-scanning direction. , A predetermined pattern is drawn on the object to be drawn by controlling according to a clock pulse of a predetermined frequency.

In such a laser drawing apparatus, it is required that a circuit pattern is always drawn at the same position on each of a plurality of objects to be drawn of the same standard, for example, a substrate having a photoresist layer. In this case, each object to be drawn must always be accurately positioned at the same position with respect to the drawing table of the laser drawing apparatus, but actually, the drawing table of the laser drawing apparatus has the same standard. There is no precise positioning of each of the objects to be drawn at the same position. The reason is that the drawing accuracy of such a laser drawing apparatus is on the order of microns, and therefore, a positioning mechanism for positioning the object to be drawn on the drawing table with an accuracy on the order of microns is very expensive. Further, such a positioning mechanism needs to be compatible with objects to be drawn of various standards, which makes the positioning mechanism more expensive.

Therefore, conventionally, positioning marks provided at the four corners of the object to be drawn are solid-state image pickup devices such as CCDs (charge-charged).
coupled device) etc.
The center coordinate data of the image of the positioning mark is obtained by the pattern matching method, the relative position data of the object to be drawn with respect to the drawing table is calculated based on the center coordinate data, and the position along the main scanning direction is calculated based on the relative position data. The drawing start position by the laser beam and the drawing start position by the laser beam along the sub-scanning direction are controlled, so that the drawing pattern is always positioned at the same position for each of a plurality of objects to be drawn of the same standard. .

As is well known, the pattern matching method is image processing software developed for identifying characters, marks, and the like drawn on a printed wiring board or the like. It is also used as an arithmetic method for obtaining data. In this case, in order to obtain the center coordinate data of the positioning mark, it is necessary to previously register a pattern similar to the positioning mark in the memory as a registration pattern using a registration window. Is performed through input means such as a keyboard and a mouse while viewing a display screen of a CRT display device or the like.

When a pattern similar to the positioning mark is registered in the memory as a registration pattern using the registration window, the center of the pattern must exactly match the center of the registration window. That is, when calculating the center coordinate data of the positioning mark by performing pattern matching on the positioning mark using the registration pattern, the calculation is performed not on the center coordinate data of the registration pattern but on the center coordinate of the registration window. This is because it is performed based on data. That is, if the center of the pattern is shifted from the center of the registration window when the pattern is registered as described above, the shift will be taken in as an error when calculating the center coordinate data of the positioning mark. .

However, since the resolution of a display screen of a CRT display device or the like does not reach a precision on the order of microns, it is practically necessary to register the pattern by making the center of the pattern exactly coincide with the center of the registration window. Impossible. That is, when a pattern is registered, a shift of the center of the pattern from the center of the registration window is inevitably accompanied.

Therefore, conventionally, after a pattern similar to a positioning mark is registered in a memory as a registered pattern using a registration window, pattern matching and drawing operations are performed on a trial basis based on the registered pattern. The positional deviation between the obtained drawing pattern and the positioning mark of the object to be drawn is actually measured, and the center coordinates of the registration window are corrected based on the measured value to obtain the center coordinates data of the registration pattern. In short, the correction data is stored in a non-volatile memory or the like, and at the time of an actual drawing operation, the calculation of the center coordinate data of the positioning mark by the pattern matching method is performed in consideration of the correction data. Appropriate and accurate relative position data of the object to be drawn with respect to the table can be obtained.

[0011]

However, as a conventional problem, in order to find a deviation between the center of the registered pattern and the center of the registered window, a drawing operation must be performed on a trial basis after the registered pattern is created. However, this is very complicated and troublesome. This is because, when performing such a test drawing operation, an object to be drawn is prepared by applying a photographic emulsion on a glass plate, and a test pattern, for example, is drawn as a drawing pattern on the surface of the photographic emulsion. This is because the position deviation between the test pattern and the positioning mark must be measured after the pattern is developed, and such work must be performed according to the type of the pattern shape of the positioning mark on the object to be drawn. It is.

Accordingly, a first object of the present invention is to easily and accurately find the deviation between the center of a registered pattern and the center of a registered window in the pattern matching method, and to accurately calculate the center coordinate data of the registered pattern. An object of the present invention is to provide an arithmetic device configured as described above.

[0013] A second object of the present invention is a laser writing apparatus using the above-described arithmetic unit, which performs a writing operation after the registration pattern is created in order to determine a deviation between the center of the registration pattern and the center of the registration window. It is an object of the present invention to provide a laser writing apparatus which does not need to perform the test on a trial basis.

[0014]

SUMMARY OF THE INVENTION An arithmetic unit according to the present invention is for calculating correction data of center coordinate data of a registered pattern in a pattern matching method. Registration pattern creating means for registering in the memory as a pattern, and performing pattern matching using a registration pattern for a pattern similar to a point-symmetric pattern and located in an arbitrary coordinate system, thereby providing a temporary center of the registration pattern. First calculating means for obtaining coordinate data, registered half-rotation pattern creating means for rotating the registered pattern by 180 degrees around the center of the registration window and registering it in the memory as a registered half-rotated pattern; Pattern using the registered half-rotation pattern for a pattern that is located in an arbitrary coordinate system. A second calculating means for obtaining temporary center coordinate data of the registered half-rotation pattern by executing the ringing, and a temporary calculating means for obtaining the temporary center coordinate data of the registered pattern obtained by the first calculating means. And a third calculating means for obtaining deviation data of the center of the registration pattern with respect to the center of the registration window based on the obtained temporary center coordinate data of the registered half-rotation pattern.

A laser drawing apparatus according to the present invention performs a drawing operation by moving a drawing object in a sub-scanning direction while deflecting a laser beam in a main scanning direction with respect to the drawing object. Image pickup means provided at a predetermined position for photographing the positioning mark, and coordinate calculating means for obtaining center coordinate data of the positioning mark picked up by the image pickup means by a pattern matching method. Based on the obtained center coordinate data of the positioning mark, the drawing start position by the laser beam along the main scanning direction and the drawing start position by the laser beam along the sub-scanning direction are controlled. According to the present invention, in such a laser writing apparatus, the storage means for storing the correction data calculated by the above-described processing apparatus, and the coordinate calculation means are controlled based on the correction data stored in the storage means. A correction processing unit for correcting the center coordinate data of the positioning mark of the drawing body is provided.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the configuration of an arithmetic unit according to the present invention and a laser drawing apparatus using the arithmetic unit.

FIG. 1 is a perspective view schematically showing a laser writing apparatus incorporating an arithmetic unit according to the present invention. The laser writing apparatus includes a circuit on a photoresist layer on a substrate for manufacturing a printed circuit board. It is configured so that a pattern can be directly drawn.

The laser drawing apparatus includes a base 10 mounted on a floor, and a pair of rails 12 are installed on the upper surface of the base 10 in parallel. X on a pair of rails 12
The X table 14 is mounted on a pair of rails 12 by a suitable drive motor not shown in FIG. 1, such as a servo motor or a stepping motor.
Along the sub-scanning direction (X-axis).

A drawing table 18 is provided on the X table 14 via a θ table 16, and two fine adjustment drivers 20 are provided on each of the sides facing each other between the X tables 14. The rotation position in the horizontal plane is finely adjusted. Note that FIG. 1 shows only two fine adjustment drivers 20 provided on one side to avoid complication of the drawing. When the X table 14 is moved in the sub scanning direction (X axis), the drawing table 18 is also moved in the sub scanning direction together with the θ table 16.

On the drawing table 18, a substrate having a photoresist layer is conveyed and placed as an object to be drawn by a suitable conveying means such as a belt conveyor, and the substrate is fixed on the drawing table 18 by a suitable clamping means. Is done. FIG. 1 shows a clamp member 22 which forms a part of the clamp means.

An argon laser generator 24 as a laser light source is installed on one side of the base 10, and a laser beam LB emitted from the argon laser generator 24 is deflected upward by a beam bender 26. On the other hand, a fixed table 28 supported by a suitable support structure (not shown) is disposed above the drawing table 18. The fixed table 28 is used to process the laser beam LB deflected by the beam bender 26. Are installed. In the present embodiment, the argon laser generator 24 is of a water-cooled type, and its output is, for example, 1.8 W.
And the wavelength of the laser is 488 nm.

The fixed table 28 is provided with a beam bender 30. The beam bender 30 receives the laser beam LB from the beam bender 26 and
Pointed to 2. The beam splitter 32 splits the laser beam LB into two laser beams LB1 and LB2. Laser beam LB1 is directed to beam separator 38 via beam benders 34 and 36, and laser beam LB2 is directed to beam separator 46 via beam benders 40, 42 and 44.

The beam separator 38 is a laser beam LB
1 is divided into, for example, eight parallel laser beams, and the beam separator 46 similarly divides the laser beam LB2 into eight parallel laser beams. The parallel laser beam from the beam separator 38 is guided to the electronic shutter 52 by beam benders 48 and 50, and
Are guided to an electronic shutter 58 by beam benders 54 and 56.

Each of the electronic shutters 52 and 58 includes eight acousto-optic devices, and each acousto-optic device is assigned a corresponding one of the eight laser beams. The eight laser beams passing through the electronic shutter 52 are incident on the photosynthesizer 60, while the eight laser beams passing through the electronic shutter 58 are incident on the photosynthesizer 60 via the beam bender 62. The light combiner 60 is configured as, for example, a polarization beam splitter, and the eight laser beams that have passed through the electronic shutters 52 and 58 are combined into 16 laser beams by the light combiner (polarization beam splitter) 60. The 16 laser beams are made incident on the polygon mirror 70 via the beam benders 64, 66 and 68, and are deflected along the main scanning direction (Y axis) by their respective rotating reflection surfaces.

The 16 laser beams deflected along the main scanning direction by the respective rotating reflection surfaces of the polygon mirror 70 are first passed through the fθ lens 72 and then directed by the turning mirror 74 to the drawing table 18 side. The light is made to reach the drawing table 18 via the condenser lens 76. In short, the object to be drawn set on the drawing table 18 is scanned by the sixteen laser beams deflected in the main scanning direction by the respective rotating reflection surfaces of the polygon mirror 70.

Accordingly, a substrate having a photoresist layer as an object to be drawn is placed on the drawing table 18 as described above, and the surface of the photoresist layer on the substrate is deflected by the rotating reflection surfaces of the polygon mirror 70. When scanning is performed at once (main scanning direction) with the 16 laser beams, the eight acousto-optic elements of each of the electronic shutters 52 and 58 are operated according to a clock pulse of a predetermined frequency based on raster data. When the 16 laser beams are modulated, a predetermined circuit pattern based on the raster data is drawn on the surface of the photoresist layer.

While the 16 laser beams are deflected along the main scanning direction, the drawing table 18
Are sequentially moved along the sub-scanning direction (X-axis), and when the deflection along the main scanning direction by the 16 laser beams is completed, the moving distance of the drawing table 18 is long.
The distance corresponds to the width of the book laser beam in the sub-scanning direction. Thus, when the deflection along the main scanning direction by the 16 laser beams is repeated, a predetermined circuit pattern is sequentially drawn on the surface of the photoresist layer on the substrate.

Assuming that the main scanning direction and the sub-scanning direction are perpendicular to each other, the drawing line of the 16 laser beams along the main scanning direction is inclined with respect to the sub-scanning direction (X axis). That is, as described above, while the 16 laser beams are deflected along the main scanning direction, the drawing table 18 is sequentially moved by the X table 14 at a predetermined speed along the X axis direction, that is, the sub scanning direction. This is because they have been moved. However, in practice, the main scanning direction is X
The laser beam is tilted by a predetermined angle with respect to the axial direction in advance, so that the drawing line along the main scanning direction by 16 laser beams is perpendicular to the sub-scanning direction.

As shown in FIG.
The small imaging means, for example, CC
D cameras 78 are provided, and these CCD cameras 78 are used to accurately detect the relative position of the object to be drawn with respect to the drawing table 18 when the object to be drawn is placed on the drawing table 18 of the laser drawing apparatus. Is done.

Referring to FIG. 2, a substrate SB having a photoresist layer is shown as an example of an object to be placed on the drawing table 18, and cross-shaped positioning marks PM are provided at four corners of the substrate SB. Is appended. CCD camera 7
8, positioning marks P provided at the four corners on the substrate
When M is photographed, center coordinate data of the positioning mark is obtained based on the video signal. CCD camera 7
8 itself is fixedly supported at a predetermined position with respect to a machine frame (not shown) of the laser drawing apparatus, and thus, the relative position of the substrate SB with respect to the drawing table 18 is obtained by obtaining the center position coordinate data of the positioning mark on the substrate. Can be specified.

Referring to FIG. 3, there is shown a block diagram of a laser writing apparatus according to the present invention.
Reference numeral 80 indicates a system control circuit. The system control circuit 80 includes, for example, a microprocessor such as a central processing unit (CPU) and a memory (RO).
M, RAM) and the like.

The two CCD cameras 78 shown in FIG. 1 are connected to the system control circuit 80 via an image processing circuit 82. The CCD camera 78 reads the positioning marks provided at each of the four corners of the substrate having the photoresist layer as a video signal, and the video signal is subjected to predetermined image processing by the image processing circuit 82 and further processed by the pattern matching method. Thus, the center coordinate data of the positioning mark is obtained.

As apparent from FIG. 3, the system control circuit 80 controls the operation of the main scanning control circuit 84. The main scanning control circuit 84 controls the operation of the above-described electronic shutters 52 and 58. Is provided. As shown in FIG. 4, the beam position control circuit 86 includes a buffer memory 86A and a synchronous circuit 8A.
6B. At the time of the drawing operation, the raster data output from the raster conversion circuit 88 (FIG. 3) is sequentially written and temporarily stored in the buffer memory 86A, and the raster data is sequentially read from the buffer memory 86A and synchronized. Output to the circuit 86B. Writing of raster data to the buffer memory 86A is performed based on a write clock pulse output from the system control circuit 80 to the buffer memory 86A, and reading of raster data from the buffer memory 86A is performed by the system control circuit 80. This is performed based on the read clock pulse output to the memory 86A.

A data storage means controlled by the system control circuit 80, for example, a hard disk drive (not shown) is provided in the control section of the laser drawing apparatus. This hard disk drive is prepared and processed by a CAD station or a CAM station. The circuit pattern data (vector data) is transferred as necessary, and at the time of drawing operation, the corresponding circuit pattern data is read from the hard disk device and converted into raster data by the raster conversion circuit 88. Further, in the present embodiment, since the drawing by the 16 laser beams is performed simultaneously during the drawing operation, the buffer memory 86A has a capacity capable of storing at least 16 lines of raster data in the main scanning direction. Is done.

During the drawing operation, the beam position control circuit 8
Raster data of 16 lines in the main scanning direction read out from the buffer memory 86A are sequentially input to the synchronization circuit 86B of No. 6, and a clock pulse of a predetermined frequency output from the system control circuit 80 is also input. The electronic shutters 52, 5
A control voltage signal is output to each of the acousto-optic elements included in 8 based on the corresponding raster data.

More specifically, when each of the control voltage signals output from the synchronization circuit 86B is input to each of the acousto-optic element driving circuits included in the electronic shutter 52,
A high-frequency drive voltage is output from each acousto-optic element drive circuit to the corresponding acousto-optic element and applied. The voltage level of the control voltage signal output to each acousto-optic element drive circuit is changed based on the corresponding raster data,
Accordingly, the level of the high-frequency drive voltage output from each acousto-optic element driving circuit to the corresponding acousto-optic element is also changed, whereby the diffraction direction of the laser beam passing through each acousto-optic element is changed. That is, when the pixel of the raster data is a color pixel (ie, “1” as digital pixel data), the laser beam is diffracted toward the light combiner 60, and the pixel of the raster data is a non-color pixel (ie, When the digital pixel data is “0”), the laser beam is diffracted so as to be out of the light combiner 60.

Similarly, a control voltage signal output from the synchronizing circuit 86B is also input to each of the acousto-optical element driving circuits included in the electronic shutter 58. At this time, a high-frequency driving voltage is applied from each acousto-optical element driving circuit. The high-frequency driving voltage is output and applied to the acousto-optic element, and the level of the high-frequency driving voltage is changed based on the corresponding raster data. In the case of the electronic shutter 58, the pixels of the raster data are colored pixels (that is, "1" as digital pixel data).
, The laser beam is diffracted toward the beam bender 62, and when the pixel of the raster data is a non-colored pixel (ie, “0” as digital pixel data), the laser beam deviates from the beam bender 62. Is diffracted.

In short, only when the pixel of the raster data is a coloring pixel, the corresponding laser beam is directed to the polygon mirror 70, and a dot is recorded as a coloring pixel on the drawing object on the drawing table 18. Therefore, by modulating each laser beam with the electronic shutters 52 and 58 based on the corresponding raster data as described above, a circuit pattern based on the raster data is drawn on the drawing target on the drawing table 18. become.

As shown in FIG. 3, the main scanning control circuit 84 is further provided with a Y scale sensor 90 and a signal processing circuit 92. The Y scale sensor 90 detects an optical signal from a Y linear scale (not shown) to measure the deflection distance of the laser beam along the main scanning direction, and is well known in itself. Y scale sensor 90
The output signal from is appropriately processed by the signal processing circuit 92 and is taken into the system control circuit 80.
A clock pulse to the synchronization circuit 86B is created based on the output signal.

As is clear from FIG. 3, the system control circuit 80 further controls the operation of the sub-scanning control circuit 94. The sub-scanning control circuit 94 is provided with a servo motor driving circuit 96, The drive of the servo motor 98 is controlled by 96. Servo motor 9
Numeral 8 is for moving the X table 14 at a predetermined speed in the X-axis direction, that is, in the sub-scanning direction, whereby the object to be drawn on the drawing table 18 is moved in the sub-scanning direction. At the time of drawing operation, a clock pulse of a predetermined frequency is output from the system control circuit 80 to the servo motor driving circuit 96, and the driving pulse is output from the servo motor driving circuit 96 based on the clock pulse.
8 is output.

As shown in FIG. 3, the sub-scanning control circuit 94 further includes an X scale sensor 100 and a signal processing circuit 102.
Is provided. The X scale sensor 100 detects an optical signal from an X linear scale (not shown) and measures the moving distance of the drawing table 18 (that is, the object to be drawn) along the main scanning direction. Itself is well known. The output signal from the X-scale sensor 100 is appropriately processed by the signal processing circuit 102 and then taken into the system control circuit 80, and a clock pulse to the servo motor drive circuit 96 is created based on the output signal.

As shown in FIG. 3, a CRT display device 104 is connected to the image processing circuit 82 as a display device, and a keyboard 106 and a mouse 1 are used as input means.
08 is connected. In the present embodiment, the image processing circuit 82
The microprocessor itself and the memory (R) such as a central processing unit (CPU) are similar to the system control circuit 80 itself.
OM, RAM) and the like, and may be, for example, a commercially available personal computer.

As described above, in order to accurately specify the relative position of the object to be drawn with respect to the drawing table 18, the positioning mark of the object to be drawn is photographed by the CCD camera 78 and the center coordinate data of the positioning mark is obtained. It is necessary. According to the present invention, a pattern matching method is employed to obtain the center coordinate data of the positioning mark. At this time, a pattern similar to the positioning mark is registered in a memory as a registration pattern by using a registration window. It is necessary to know the center coordinate data of the registered pattern in advance.

As described above, conventionally, a pattern similar to the positioning mark is registered in the memory as a registered pattern using a registration window, and then a pattern matching method and a drawing operation are experimentally performed based on the registered pattern.
The positional deviation between the drawing pattern obtained at that time and the positioning mark of the object to be drawn was actually measured, and the center coordinates of the registration window were corrected based on the measured value as the center coordinate data of the registration pattern. According to this, it is possible to easily obtain the center coordinate data of the registered pattern without performing a trial drawing operation. That is, in the present invention, the center coordinate data of the registered pattern is obtained by the image processing circuit 82, and the calculation is performed by operating the keyboard 106 and the mouse 108 while viewing the display screen of the CRT display device 104. Be executed.

Referring to FIG. 5, there is shown a flowchart of a calculation routine for obtaining the center coordinate data of the registered pattern in the pattern matching method. FIGS. 6 to 10 schematically show the main steps of the flowchart. It is shown.

When a command to start execution of the arithmetic routine is input through the keyboard 106, various patterns are displayed on the display screen of the CRT display device 104, and a predetermined pattern is selected from the various patterns. A message prompting registration in the memory using the registration window is also displayed (step 501). Therefore, the operator selects a pattern similar in shape to the positioning mark used for the object to be drawn, that is, the substrate, and performs an operation of surrounding the pattern with a registration window. When such an operation is completed, it is determined whether or not a registration execution command has been input by the operator via the keyboard 106 (step 502). When a registration execution command is input, a predetermined pattern surrounded by a registration window is registered in the memory as a registration pattern (step 503).

More specifically, for example, the mouse 108
, A predetermined pattern (similar to the positioning mark) is selected from various patterns, and the operation of surrounding the pattern with the registration window is performed. FIG. 6 shows a state in which such a predetermined pattern P is surrounded by a registration window RW, and a cross line drawn in the center of the registration window RW indicates the center of the registration window. The shape of the positioning marks PM at the four corners of the substrate SB shown in FIG. 2 is similar to the pattern P.

If the pattern P is registered in the registration window RW in the state shown in FIG. 6, the center of the registration pattern P remains shifted from the center of the registration window RW, as is apparent from FIG. . In FIG. 6, the amount of deviation between the center of the registration pattern P and the center of the registration window RW is exaggerated. However, it is a fact that the centers of the two coincide exactly for the reason described above. It is impossible.

After the registration pattern is created, the positioning mark PM on the substrate SB is captured by the CCD camera 78 and image-processed, and the pattern matching is performed using the registration pattern P on the positioning mark pattern PM '(step 5).
04) At this time, as shown in FIG. 7, the center coordinate data (Xa, Ya) of the registration window RW is obtained as temporary data as the center coordinates of the positioning mark PM (pattern PM ') on the substrate SB (step 505). . of course,
Such provisional data includes an error corresponding to a shift amount between the center of the registration pattern P and the center of the registration window RW. An XY coordinate system is set on the drawing table 18, and the positioning mark PM on the substrate SB set on the drawing table 18 is positioned in the XY coordinate system, thereby obtaining the coordinate data. .

Next, image processing for rotating the registered pattern P by half a 180 degree around the center of the registration window RW is executed, and the half-rotated pattern is registered in the memory as a registered half-rotated pattern (step 506). Is created as shown in FIG. Subsequently, pattern matching is performed on the positioning mark pattern PM ′ using the registered half-rotation pattern P ′ (step 507).

At this time, as shown in FIG. 9, the center coordinate data (Xb, Yb) of the registration window RW is obtained as temporary data as the center coordinates of the positioning mark PM (pattern PM ') on the substrate SB (step 508). . Of course, such provisional data also includes an error corresponding to the amount of deviation between the center of the registered half-rotation pattern P ′ and the center of the registered window RW.

Next, the following operation is performed (step 509). Xe ← (Xb−Xa) / 2 Ye ← (Yb−Ya) / 2 As is clear from FIG. 10, the calculation result (Xe, Ye) is the registration pattern P with respect to the center coordinates of the registration window RW.
Indicates the amount of deviation of the center coordinates of the image.

The result of such an operation, that is, the registered pattern P
The center coordinate data (Xe, Ye) of a non-volatile memory provided in the image processing circuit 82, for example, EAROM, EEP
The correction data is stored as a correction data in a ROM or an SRAM having a backup power supply (step 510), and a message indicating that the calculation of the center coordinate data of the registration pattern P is completed is displayed on the display screen of the CRT display device (step 512). Thereafter, the calculation routine ends.

As is apparent from the above description, according to the present invention, the center coordinate data of the registered pattern can be easily obtained without performing a test drawing operation which is conventionally required. In the actual drawing operation, when pattern matching is performed on the positioning mark of the object to be drawn using the registered pattern P, the read value obtained by reading the coordinate value of the positioning mark PM on the actual substrate SB is ( Xc, Yc), the corrected coordinate value (Xp, Yp) in which the displacement of the registered pattern has been corrected is obtained by the following calculation. Xp ← Xc + Xe Yp ← Yc + Ye

In the above-described embodiment, a cross pattern is used as the shape of the positioning mark.
It is possible to use any other pattern as the shape of the positioning mark. However, in the present invention, such a pattern needs to be processed by half a 180-degree rotation. It needs to be point symmetric about the center.

The laser writing apparatus according to the present invention uses the correction data (X) stored in the nonvolatile memory in the image processing circuit 82.
e, Ye) to perform the drawing operation. FIG. 11 shows a flowchart of a drawing operation routine executed by the laser drawing apparatus according to the present invention, and the operation of the laser drawing apparatus according to the present invention will be described below with reference to this flowchart.

First, in step 1101, the servo motor drive circuit 96 is operated, whereby the drawing table 18 is moved from the origin position. Drawing table 1
8 (ie, a substrate having a photoresist layer)
The drawing table 18 is temporarily stopped at a position where a pair of positioning marks along one side in the main scanning direction (Y-axis direction) can be captured in the field of view of the two CCD cameras 78, 78. Next, in step 1102, pattern matching is performed on the positioning marks taken by the CCD cameras 78, 78 using the registered pattern P, the center coordinate data of the positioning marks is calculated, and the data is stored in the memory of the system control circuit 80. For example, it is stored in a RAM.

In step 1103, the servo motor drive circuit 96 is operated again, whereby the drawing table 18 is further moved. The drawing table 18 is stopped again at a position where a pair of positioning marks on the drawing table 18 along the other side in the main scanning direction of the object to be drawn are captured in the field of view of the two CCD cameras 78, 78.
Next, in step 1104, the CCD cameras 78, 7
Registration pattern P with respect to the positioning mark
Is used to calculate the center coordinate data of the positioning mark, and is stored in the memory of the system control circuit 80, for example, RAM.

In step 1105, drawing start position data in the sub-scanning direction, that is, X-axis drawing start position data, based on the relative position data of the object to be drawn with respect to the drawing table 18 formed by the center coordinate data of the positioning marks. Drawing start position data along the main scanning direction by the laser beam, that is, Y-axis direction drawing start position data is calculated.

In step 1106, the drawing table 18
Is moved and stopped at the drawing start position based on the X-axis drawing start position data obtained in step 1105. Next, at step 1107, a drawing operation is performed. At this time, the drawing start position along the main scanning direction by the laser beam is determined based on the Y-axis drawing start position data obtained at step 1106.

In step 1108, it is determined whether or not the drawing operation has been completed. When the completion of the drawing operation is confirmed, the process proceeds from step 1108 to step 1109, where the drawing table 18 is returned to the origin position. afterwards,
This drawing operation routine ends.

In the above embodiment, the CCD camera 78 is fixedly supported at a predetermined position with respect to the machine frame of the laser drawing apparatus, and the positioning mark PM on the substrate SB is
Although the drawing table 18 is moved to capture the field of view 8, if the CCD camera 78 is made movable and the amount of movement can be measured, the CCD camera 7 is moved.
8, the positioning mark PM on the substrate SB can be captured in the field of view.

[0063]

As is apparent from the above description, according to the present invention, the center coordinate data of the registered pattern in the pattern matching method can be obtained accurately and easily, so that the positioning by the pattern matching method can be easily implemented. In addition, it can contribute to its spread.

Further, according to the present invention, the drawback caused by the accuracy problem associated with the laser writing apparatus using the conventional pattern matching method is eliminated, that is, the deviation between the center of the registration pattern and the center of the registration window. Since it is not necessary to perform a drawing operation on a trial basis after the creation of the registered pattern in order to obtain the value, it can contribute to an improvement in the drawing operation efficiency of the laser drawing apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a laser drawing apparatus according to the present invention.

FIG. 2 is a plan view of an object to be drawn placed on a drawing table of the laser drawing apparatus shown in FIG.

FIG. 3 is a block diagram of the laser drawing apparatus shown in FIG. 1 and an arithmetic unit used therein.

FIG. 4 is a detailed block diagram of a beam position control circuit shown in FIG.

FIG. 5 is a flowchart showing a registration pattern center coordinate data calculation routine executed by the calculation device according to the present invention.

FIG. 6 is a schematic diagram schematically showing one of the main steps of the flowchart shown in FIG. 5;

FIG. 7 is a schematic diagram schematically showing one of the main steps of the flowchart shown in FIG. 5;

FIG. 8 is a schematic diagram schematically showing one of the main steps of the flowchart shown in FIG. 5;

FIG. 9 is a schematic diagram schematically showing one of the main steps of the flowchart shown in FIG. 5;

FIG. 10 is a schematic diagram schematically showing one of the main steps of the flowchart shown in FIG. 5;

FIG. 11 is a flowchart showing a drawing operation routine executed by the laser drawing apparatus according to the present invention.

[Explanation of symbols]

 14 X table 18 Drawing table 24 Argon laser generator 52/58 Electronic shutter 70 Polygon mirror 78 CCD camera 80 System control circuit 82 Image processing circuit 84 Main scanning control circuit 86 Beam position control circuit 88 Raster conversion circuit 90 Y scale sensor 92 Signal Processing circuit 94 Sub-scanning control circuit 96 Servo motor drive circuit 98 Servo motor 100 X scale sensor 102 Signal processing circuit 104 CRT display device 106 Keyboard 108 Mouse

Claims (2)

[Claims] 1. An arithmetic unit for calculating correction data of center coordinate data of a registered pattern in a pattern matching method, comprising: a registered pattern creating means for registering a point-symmetric pattern as a registered pattern in a memory using a registration window; A first calculation for obtaining temporary center coordinate data of the registered pattern by executing a pattern matching method using the registered pattern on a pattern similar to the point symmetric pattern and located in an arbitrary coordinate system; Means for registering the registration pattern around the center of the registration window;
A registered half-rotation pattern creating means for rotating the half-rotation by 0 degree and registering it in a memory as a registered half-rotation pattern; and A second calculating means for obtaining temporary center coordinate data of the registered half-rotation pattern by executing a pattern matching method by using the temporary center coordinate data of the registered pattern obtained by the first calculating means. A third calculating means for obtaining deviation data of the center of the registration pattern with respect to the center of the registration window based on the temporary center coordinate data of the registered half-rotation pattern obtained by the second calculating means. Arithmetic unit consisting of 2. A laser writing apparatus which performs a writing operation by moving a drawing object in a sub-scanning direction while deflecting a laser beam in a main scanning direction with respect to the drawing object, and positioning the drawing object. An image pickup means provided at a predetermined position for photographing a mark; and coordinate calculating means for obtaining center coordinate data of the positioning mark picked up by the image pickup means by a pattern matching method. A laser drawing apparatus, wherein a drawing start position by the laser beam along the main scanning direction and a drawing start position by the laser beam along the sub-scanning direction are controlled based on the center coordinate data of the positioning mark. Storage means for storing the correction data calculated by the calculation device described in 1, and the coordinate calculation means stores the correction data in the storage means. The laser drawing apparatus, characterized in that the and the correction processing means for correcting processing center coordinate data of the positioning mark of the drawing member is provided based on the correction data.