JP2007237199A - Laser beam machining apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain highly accurate laser beam machining by preventing deviation of an irradiation position of a laser beam caused by thermal deformation of a workpiece. <P>SOLUTION: An apparatus 20 for performing laser beam machining on a prescribed region by irradiating a plurality of positions of a workpiece 32 with a laser beam is provided with: a machining stage 25 for placing the workpiece 32 on; a machining stage driving means 26 for moving the machining stage 25 to the plurality of positions; a position detecting means 27 for detecting the positions of the machining stage 25; a thickness measuring means 29 for measuring the thickness of the workpiece 32; and a control means 31 that, on the basis of the machining conditions of the workpiece 32, picks up a specific correction pattern from those for a plurality of machining conditions which are preliminarily stored and that, by the correction pattern so picked up, controls to correct the irradiation positions of the laser beam. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laser processing apparatus and a laser processing method, and more particularly to a laser processing apparatus and a laser processing method for preventing laser beam irradiation position shift due to thermal deformation of a workpiece and realizing highly accurate laser processing. About.

  Conventionally, when laser processing is performed on a predetermined region by irradiating a plurality of positions on a processing target such as a glass substrate and performing laser processing on a predetermined region, the temperature of the processing target is increased by irradiating the processing target with laser light for a long time. It rises and heat deformation (expansion) is known to occur. Further, due to this thermal deformation, the irradiation position shifts during processing. In particular, when performing an annealing process for continuously growing a crystal, it is necessary to grow the crystal with high positional accuracy.

  Here, the above-mentioned content is demonstrated using figures. FIG. 1 is a diagram for explaining the outline of the annealing process on a workpiece. For example, when the annealing process is performed on the processing object, the processing object is irradiated with a laser beam imaged to a predetermined size through a mask as shown in FIG.

  Further, as shown in FIG. 1B, an accurate annealing process is performed by scanning at a predetermined direction and speed while irradiating the workpiece with laser light at a predetermined pulse interval. At this time, accurate and highly accurate irradiation is required at a predetermined interval K so as not to cause a deviation between adjacent irradiation regions.

  In addition, the scan described above is performed for the number of rows set in advance for the workpiece 11 as shown in FIG. 1C, and a predetermined region is annealed. In the annealing process, as shown in FIG. 1, laser light is sequentially irradiated to adjacent regions. Thereby, since the movement of a processing target object can be decreased, processing efficiency is good.

  Note that the surface of the workpiece 11 has a plurality of alignment marks 12-1 to 12-4 in order to align the irradiation position of the laser beam. When laser processing is performed, the irradiation position of the laser beam on the processing object 11 is confirmed using an alignment mark by a camera or the like made up of a CCD (Charge Coupled Devices) imaging device, and laser processing by irradiation is performed.

  Here, when the process as shown in FIG. 1 is performed, the thermal deformation of the workpiece 11 as described above occurs. FIG. 2 is a diagram illustrating an example of a thermally deformed workpiece. FIG. 2 exaggerates the amount of deformation. As shown in FIG. 2, since the workpiece 11 is deformed (expanded) by continuous laser light irradiation, there is a problem that a preset laser light irradiation position is also shifted.

Therefore, conventionally, a method for correcting the positional deviation as described above has been disclosed (for example, see Patent Document 1). The technique disclosed in Patent Document 1 realizes high-accuracy exposure by removing alignment errors caused by expansion and contraction of the substrate and the substrate holder during exposure. Specifically, it has a relative position measurement device that measures the relative displacement between the substrate stage and the substrate holder, and corrects the position of the substrate stage measured by the stage position measurement device by the measured relative displacement. To do. Therefore, it is possible to prevent deterioration in overlay accuracy due to expansion of the substrate during exposure.
JP 11-87228 A

  However, since the technique disclosed in Patent Document 1 described above measures the relative displacement between the substrate stage and the substrate holder during exposure, it takes time for exposure processing. Therefore, in laser processing, it is preferable to predict a positional deviation in advance and correct the irradiation position in consideration of the positional deviation due to thermal deformation from the content.

  Further, the above-described thermal deformation of the object to be processed varies depending on processing conditions such as the type of laser light to be irradiated and the material of the object to be processed, but the thickness of the object to be processed in particular has a great influence on the thermal deformation. For example, when the workpiece is a thin substrate having a thickness of about 0.7 mm, there is usually an error (variation) of about ± 0.1 mm depending on the workpiece, but the amount of thermal deformation varies greatly even with this error. End up. Accordingly, it is necessary to generate a correction pattern corresponding to the thickness of the workpiece, but there has been no such correction method in the past.

  The present invention has been made in view of the above-described problems, and prevents laser beam irradiation position displacement due to thermal deformation of an object to be processed, and laser processing apparatus and laser processing for realizing high-precision laser processing. It aims to provide a method.

In order to achieve the above-described object, the present invention provides a processing stage for placing a processing object in a laser processing apparatus that performs laser processing on a predetermined region by irradiating a plurality of positions of the processing object with laser light. Machining stage driving means for moving the machining stage to the plurality of positions, position detection means for detecting the position of the machining stage, thickness measuring means for measuring the thickness of the workpiece, and a machining target Control means for obtaining a specific correction pattern from correction patterns for a plurality of processing conditions accumulated in advance based on the processing conditions for the object, and performing control to correct the irradiation position of the laser beam by the acquired correction pattern; It is characterized by having. Thereby, the shift | offset | difference of the irradiation position of the laser beam by the thermal deformation of a workpiece is prevented, and highly accurate laser processing can be realized. Further, since laser processing is performed using the irradiation position of the laser light corrected by the correction pattern accumulated in advance, the laser processing time can be shortened.

  Further, it is preferable that the control means obtains a specific correction pattern from correction patterns for a plurality of processing conditions accumulated in advance using the thickness of the workpiece obtained by the thickness measurement means as the processing condition. Thereby, the shift | offset | difference of the irradiation position of the laser beam by the thermal deformation of a workpiece can be prevented with high accuracy.

  Furthermore, the control means includes a plurality of pre-stored plural processing conditions as at least one of the laser beam type, pulse energy, material to be processed, volume, mask slit shape, processing path, and processing speed. It is preferable to acquire a specific correction pattern from the correction pattern for the processing conditions. Thereby, an optimal correction pattern can be acquired based on detailed processing conditions.

  Furthermore, it has an image pickup means for taking an image of the alignment mark formed on the object to be processed, and the control means is taken by the image pickup means after the laser processing and a theoretical value as a preset laser beam irradiation position. It is preferable to measure the positional deviation amount based on the actual measurement value obtained from the obtained image data and generate a correction pattern from the measured positional deviation amount. Thereby, the shift | offset | difference of the irradiation position of the laser beam by the thermal deformation of a workpiece is prevented, and highly accurate laser processing can be realized.

  Furthermore, it is preferable that the control means generates at least one correction pattern among the entire predetermined area, every predetermined moving area, and every irradiation position. Thereby, a detailed correction pattern can be obtained. Therefore, a more optimal correction pattern can be acquired.

  Further, the present invention provides a laser processing method for performing laser processing on a predetermined region by irradiating a plurality of positions on a processing object with laser light, based on a theoretical value as a preset irradiation position of the laser light. An irradiation step of irradiating a plurality of positions with laser light, an acquisition step of acquiring positions actually irradiated by the irradiation step, and a deviation for measuring a deviation amount between the theoretical value and an actual value obtained by the acquisition step An amount measuring step, a correction pattern generating step for generating a correction pattern from a deviation amount obtained by the deviation amount measuring step, and an accumulation step for storing the correction pattern obtained by the correction pattern generation step in accordance with a processing condition It is characterized by having. Thereby, the deviation | shift of the irradiation position of the laser beam by the thermal deformation of a workpiece is prevented using the accumulated correction pattern, and highly accurate laser processing can be realized.

  Furthermore, it has a thickness measurement step for measuring the thickness of the workpiece, and the accumulation step accumulates the thickness measured in the thickness measurement step in correspondence with the correction pattern, using the thickness as a machining condition. It is preferable. Thereby, the shift | offset | difference of the irradiation position of the laser beam by the thermal deformation of a workpiece can be prevented with high accuracy.

  Furthermore, it is preferable that the correction pattern generation step generates at least one correction pattern among the entire predetermined area, every predetermined movement area, and each irradiation position. Thereby, a detailed correction pattern can be obtained.

  Further, a search step for searching for a correction pattern corresponding to the same processing condition as a processing condition at the time of a new processing from the stored data stored in the storage step, and a correction pattern obtained by the search step, It is preferable to include a correction step for correcting the irradiation position, and a processing step for processing the object to be processed by irradiating the irradiation position corrected by the correction step with a laser beam. Thereby, the deviation | shift of the irradiation position of the laser beam by the thermal deformation of a workpiece is prevented using the accumulated correction pattern, and highly accurate laser processing can be realized. Further, since laser processing can be performed using the irradiation position of the laser light corrected by the correction pattern accumulated in advance, the laser processing time can be shortened.

  Further, in the deviation amount measuring step, a mask provided with a hole for attaching a laser irradiation trace for deviation confirmation to an alignment mark provided corresponding to a preset irradiation position of the workpiece by the irradiation step. It is preferable that the amount of deviation is measured from the image of the alignment mark and the laser irradiation mark taken by the acquisition step. Thereby, the amount of deviation can be acquired with high accuracy.

  ADVANTAGE OF THE INVENTION According to this invention, the shift | offset | difference of the irradiation position of the laser beam by the thermal deformation of a workpiece is prevented, and highly accurate laser processing can be realized.

<Outline of the present invention>
The present invention relates to a laser beam irradiation position that is set on the premise that thermal deformation does not occur in advance in a laser processing apparatus that performs laser processing on a predetermined region by irradiating a plurality of positions of a workpiece with laser light. Laser processing of the workpiece is performed based on (theoretical value), an irradiation position (actual value) generated by thermal deformation of the workpiece is acquired, and a deviation amount of the irradiation position is measured. Further, a correction pattern of the irradiation position is generated based on the measured deviation amount, and is stored in correspondence with the processing conditions when the generated correction pattern is processed. That is, a correction pattern corresponding to a plurality of processing conditions with different types of processing objects, types of laser light, and the like is generated, and the correction patterns are accumulated.

  When laser processing is actually performed, first, the same processing condition is searched from a plurality of processing conditions accumulated based on the processing condition, and a correction pattern corresponding to the searched processing condition is acquired. To do. Next, based on the acquired correction pattern, the preset irradiation position of the laser beam is corrected, and based on the corrected irradiation position, the workpiece is irradiated with the laser beam to perform laser processing.

  Next, a preferred embodiment of the laser processing apparatus and the laser processing method of the present invention will be described with reference to the drawings.

<Embodiment>
FIG. 3 is a diagram showing a configuration example of the laser processing apparatus according to the present invention. 3 includes a trigger generating unit 21, a laser oscillator 22, a mask 23, an imaging lens 24, a processing stage 25, a processing stage driving unit 26, a position detecting unit 27, and an imaging. Means 28, thickness measuring means 29, storage means 30, and control means 31 are provided.

  The trigger generation means 21 is controlled by a control signal obtained from the control means 31, acquires position information of the processing stage 25 detected by the position detection means 27, and compares it with a predetermined position obtained from the control means 31. When the positions coincide with each other, a trigger signal for outputting the pulse laser beam from the laser oscillator 22 is output.

The laser oscillator 22 emits pulsed laser light based on the trigger signal from the trigger generating means 21. Note that various types of laser light can be used depending on the content to be processed. For example, an XeCl excimer laser with 1 pulse energy of 1 J, an oscillation frequency of 300 Hz, and a wavelength of 308 nm can be used. . In addition, the type of laser light in the present invention is not particularly limited. For example, a KrF excimer laser having a wavelength of 248 nm, a KrCl excimer laser having a wavelength of 222 nm, a YAG laser, a CO ₂ (carbon dioxide gas) laser, or the like. It can also be used.

  The mask 23 is provided with slits (mask patterns) having a predetermined shape. Therefore, the laser light that has passed through the slit has a beam shape corresponding to the shape of the slit, and is irradiated onto the imaging lens 24. The type of the mask in the present invention is not particularly limited, and for example, a chrome mask that can be manufactured at low cost and can be manufactured in a short time can be used.

  The imaging lens 24 focuses the irradiated laser light and forms an image on the surface of the workpiece 32. In addition, although various materials and shapes can be used for the workpiece 32 in the present invention, for example, an amorphous silicon film is formed on the surface, and a glass substrate having a length of 730 mm × width of 920 mm × thickness of 0.7 mm is used. Can be used. In addition to glass, ceramic, Si semiconductor material, metal, plastic, or the like can also be used.

  The processing stage 25 is a stage for moving the mounted processing target object 32 to a predetermined position, and the processing target object 32 is fixed on the processing stage 25 by, for example, vacuum suction. Further, the processing stage driving unit 26 has a servo mechanism, and the processing stage 25 is moved to the set irradiation position by the control signal obtained from the control unit 31. The workpiece 32 is irradiated in a predetermined direction by moving in the direction (X, Y direction) perpendicular to the optical axis of the light, in the optical axis direction (Z direction), and in a predetermined inclination angle θ direction with respect to the XY plane. Move to position.

  Further, the processing stage driving unit 26 acquires the position information in the X and Y axis directions obtained by the position detecting unit 27 and the height position information of the processing stage 25 obtained from the thickness measuring unit 29 to obtain a predetermined irradiation position. Make an accurate move.

  Further, the position detection unit 27 acquires position information (X and Y directions) of the processing stage 25. The acquired position information is output to the trigger generating means 21 and the processing stage driving means 26. Here, as position information, coordinates (x, y) on the XY axes set in advance can be used.

  The image pickup means 28 is composed of, for example, a camera made up of a CCD image pickup device, and takes an image of the surface of the processing object 32 and acquires image data in the vicinity of the alignment mark formed on the processing object 32. Note that when the imaging unit 28 captures an image, the processing stage driving unit 26 moves the processing stage 25 into the field of view of the imaging unit 28 so that the vicinity of the alignment mark can be captured. Moreover, the imaging | photography means 28 may image | photograph the whole surface of a process target object. The imaging unit 28 outputs the acquired image data to the control unit 31.

  The thickness measuring means 29 is composed of a height sensor or the like, and measures the distance from the surface of the processing stage 25 and the distance from the surface of the processing object 32 by a control signal from the control means 31. Thereby, the thickness measuring means 29 acquires the thickness of the workpiece 32 based on the difference (d1−d2) between the distance d1 from the surface of the machining stage 25 and the distance d2 from the surface of the workpiece 32. be able to. Note that once d1 is measured and stored in the control means 31 or the like, thickness information can be obtained from the next object by measuring only d2. Further, the thickness measuring unit 29 outputs the measured distance information and thickness information to the control unit 31. The thickness measuring unit 29 is fixed at a predetermined height, for example, and can acquire the above-described distance information by moving the processing stage 25 in the X and Y directions.

  Further, as will be described later, the storage means 30 stores correction pattern data set according to various processing conditions such as the thickness, type and volume of the processing object, and the type of laser light source. The specific contents of the stored data stored in the storage means 30 will be described later.

  The control means 31 controls each component in order to realize laser processing for generating correction data in advance by the laser processing apparatus 20 and actual laser processing. Specifically, the control unit 31 outputs irradiation position information of the processing stage 25 at the time of processing in order to cause the trigger generating unit 21 to output a trigger signal for generating a laser pulse. Further, the control unit 31 outputs a movement control signal to the processing stage driving unit 26 in order to move the processing stage 25 to a predetermined irradiation position.

  Further, the control unit 31 outputs an acquisition control signal for acquiring thickness information to the thickness measuring unit 29, and distance information from the surface of the processing stage 25 from the thickness measuring unit 29 and the surface of the processing object 32. Distance information and the thickness information of the workpiece 32 are acquired.

  Furthermore, the control means 31 acquires image data from the imaging means 28, and based on the theoretical value as the laser beam irradiation position set in advance and the actual measurement value obtained from the image data, the processing object 32 is obtained. The amount of irradiation position deviation due to thermal deformation is acquired. The control unit 31 can also acquire the area of the processing object 32 from the image data of the imaging unit 28. The control unit 31 generates a correction pattern from the deviation amount, and associates the processing condition obtained above or the processing condition input by the operator using an input unit (not shown) and the correction pattern. Is stored in the storage means 30.

  Further, when actually performing machining, the control means 31 retrieves the same machining conditions from a plurality of machining conditions stored in the storage means 30 based on the machining conditions, and corresponds to the retrieved machining conditions. After obtaining the correction pattern and correcting the irradiation position with the correction pattern, laser processing is performed by irradiating the corrected irradiation position with the laser beam.

  As described above, the laser processing apparatus 10 can prevent the displacement of the irradiation position of the laser beam due to the thermal deformation of the object to be processed, and can realize highly accurate laser processing. Further, since laser processing is performed using the irradiation position of the laser light corrected by the correction pattern accumulated in advance, the laser processing time can be shortened.

<Accumulated data>
Here, the contents of the accumulated data accumulated in the accumulation means 30 will be described with reference to the drawings. FIG. 4 is a diagram showing a correspondence relationship between accumulated processing conditions and correction patterns. FIG. 4A shows an example in which the correction pattern corresponding to the thickness of the processing object is accumulated using the thickness of the processing object as the processing condition. As described above, for example, when the workpiece is a thin substrate having a thickness of about 0.7 mm, there is usually an error (variation) of about ± 0.1 mm depending on the workpiece. The amount varies greatly. Therefore, as shown in FIG. 4A, a correction pattern corresponding to the thickness of the workpiece is generated and stored.

  As a result, when processing is performed while changing the processing object, first, thickness information is acquired by the thickness measuring means 29, and the accumulated data shown in FIG. Get the correction pattern. Further, the irradiation position is corrected based on the correction pattern, and laser processing is performed by irradiating the corrected irradiation position with laser light. In this way, by setting the thickness of the workpiece to be a machining condition, it is possible to prevent the deviation of the irradiation position of the laser beam due to the thermal deformation of the workpiece to be performed with high accuracy.

  In addition, the correction pattern may be stored in advance corresponding to at least one of the processing conditions obtained from the laser light source, the processing target, and the mask.

  For example, as shown in FIG. 4B, if the laser light source, the type of laser light, pulse energy, etc. are processing conditions, and if it is a processing object, the material, volume (vertical, horizontal, thickness) etc. are processed. It becomes a condition. In the case of a mask, the slit shape, its size, and the like are processing conditions.

  The processing conditions are not limited to the items shown in FIG. 4B. For example, when processing a predetermined region of a processing object by irradiating a plurality of irradiation positions with laser light, the processing is performed. The route and speed are also included in the machining conditions. Of the processing conditions shown in FIG. 4B described above, conditions that cannot be acquired by the above-described apparatus configuration are input by an operator or the like.

  As shown in FIG. 4B, by accumulating correction patterns corresponding to various processing conditions, an optimal correction pattern can be acquired based on detailed processing conditions. Note that the correspondence between the processing conditions and the correction pattern shown in FIGS. 4A and 4B is an example, and the present invention is not limited to this.

<Correction pattern generation process>
Next, a correction pattern generation processing procedure according to the present invention will be described with reference to a flowchart. FIG. 5 is a flowchart showing an example of a correction pattern generation processing procedure according to the present invention. First, a laser beam is irradiated on the basis of a theoretical laser beam irradiation position (theoretical value) processing position set in advance on the assumption that the workpiece is not thermally deformed (S01). Next, a processing position processed by laser light irradiation is acquired (S02), and a deviation amount between the theoretical value and the acquired position (actual measurement value) is measured (S03). A measurement example of the positional deviation amount will be described later.

  Next, it is determined whether machining for all machining areas has been completed (S04). If machining for all machining areas has not been completed (NO in S04), the process returns to S01 and corresponds to another machining position. Then, each process of S01-S03 is performed. When processing of all processing regions is completed (YES in S04), all shift amounts at each irradiation position are measured at this time. Here, correction pattern generation processing shown in S07 described later can be performed, but in this embodiment, processing is performed a plurality of times under the same processing conditions as described above in order to improve the accuracy of the generated correction pattern.

  That is, when the processing of all the processing regions is completed (YES in S04), it is determined whether the above-described processing has been executed a predetermined number of times (S05), and the set number of times is not executed (S05). In S05, NO), the process returns to S01 and the processes of S01 to S04 are repeated. Note that, depending on the method of measuring the amount of misalignment, the processing of S01 to S04 is repeatedly performed after replacing the processing object. Further, when the preset number of times is executed (YES in S05), an average value of deviation amounts with respect to the respective irradiation positions is acquired (S06). As a result, an accurate shift amount can be acquired and the accuracy of the correction pattern can be improved.

  Further, based on the average value of the deviation amounts acquired in S06, a machining position correction pattern is generated (S07), and the correction pattern generated in S07 is as shown in FIGS. 4 (a) and 4 (b). The thickness of the processing object, the type of laser light source, the slit shape provided in the mask, the processing object such as the type and shape of the processing object are stored in association with each other (S08), and the process is terminated.

<Laser processing>
Next, a laser processing procedure using the correction pattern described above will be described using a flowchart. FIG. 6 is a flowchart showing an example of a laser processing procedure in the present invention. When performing the processing, first, based on various processing conditions that are actually performed, a correction pattern is searched from the stored data stored in advance as described above (S11). The processing conditions at this time include, for example, the thickness of the processing object, the type of the laser light source, the slit shape provided in the mask, the type of the processing object, and the like shown in FIGS. 4 (a) and 4 (b). The information obtained from each component such as the thickness measuring means in the laser processing apparatus 10 described above may be used, or information input by an operator or the like may be used.

  Next, a correction pattern corresponding to the processing condition is acquired by the search in S11 (S12), and each irradiation position (theoretical value) of the laser beam set in advance is corrected based on the acquired correction pattern (S13). Then, processing is performed by irradiating each corrected irradiation position with laser light (S14).

  As described above, since the misalignment is corrected by using the correction pattern generated in advance and the laser processing is performed, it is possible to prevent the misalignment of the laser processing due to thermal deformation and realize high-precision laser processing. . In addition, since it is not necessary to perform misalignment correction processing during processing, the processing time can be shortened.

<Measurement of misalignment>
Here, a measurement example of the positional deviation amount between the actual measurement value and the theoretical value at each machining position will be described. FIG. 7 is a diagram illustrating an installation example of alignment marks. Specifically, for example, when the deviation amount is confirmed by the imaging unit, as shown in FIG. 7A, an alignment mark 42 for confirming the deviation amount corresponding to a preset irradiation position on the entire surface of the workpiece 41. Is provided.

  Next, scan processing is performed using a mask or the like provided with a hole for attaching a mark for confirming thermal deviation (laser irradiation trace), and each alignment mark 42 and the laser irradiation trace are captured by an imaging unit 28 such as a CCD camera. A photograph is taken, and a deviation amount is measured from the photographed image by image processing. Thereby, the amount of deviation can be acquired with high accuracy.

  Further, as another example of measuring the positional deviation, for example, as shown in FIG. 1C, since alignment marks 12-1 to 12-4 are set on the processing surface of the processing target, a predetermined processing target is determined. After irradiating the entire irradiation region with laser light, the positions of the alignment marks 12-1 to 12-4 may be acquired, and the entire correction pattern may be generated from the acquired positional deviation amount. Furthermore, the position of the alignment mark after irradiating the laser beam to the predetermined movement region, such as for each row of the processing region, may be acquired, and a correction pattern may be generated from the acquired positional deviation amount.

  Further, when measuring the amount of displacement, it is better to measure the amount of displacement from the alignment mark closer to the processing position. For example, as shown in FIG. In addition to the alignment marks 12-1 to 12-4, row alignment marks 43-1a to 43-na and 43-1b to 43-nb are provided for each row of the processing region.

  Thereby, by confirming each row alignment mark by the imaging means 28, it is possible to acquire the amount of positional deviation in the vicinity of the processing region being processed with higher accuracy than in the past. The alignment mark is formed, for example, by removing a part of the silicon film on the surface of the workpiece 41 into a predetermined shape.

  In addition, the generated correction pattern generates at least one correction pattern among the entire predetermined region for irradiating the processing target with laser light, for each predetermined moving region, and for each irradiation position. Here, FIG. 8 is a diagram illustrating an example of the correction pattern. As shown in FIG. 8, the correction pattern sets a correction amount for the XY position corresponding to each irradiation position set in advance with reference to the XY position of the processing stage, for example. Thus, by having a plurality of detailed correction patterns based on processing conditions and the like, a more optimal correction pattern can be acquired.

  As described above, according to the present invention, it is possible to prevent the laser beam irradiation position from being shifted due to thermal deformation of the workpiece, and to realize highly accurate laser processing. Specifically, since a misalignment is corrected by using a correction pattern generated in advance and laser processing is performed, it is possible to prevent laser beam misalignment due to thermal deformation and realize highly accurate laser processing. it can. In addition, since it is not necessary to perform misalignment correction processing during processing, the processing time can be shortened.

  In addition, the present invention can realize high-precision laser processing even when there is an error (variation) in the thickness of the workpiece by generating a correction pattern corresponding to the thickness of the workpiece. .

  Note that the laser processing described above is not limited to laser annealing, and can be realized by, for example, forming alignment marks on the surface of an object to be processed other than laser annealing such as drilling or grooving. Can do.

  Further, in the laser processing apparatus described above, the irradiation point of the laser beam that has moved the processing stage is moved. However, the present invention is not limited to this. For example, the optical axis of the laser beam is shaken on the processing surface. The present invention can also be applied to a laser processing apparatus configured to move the irradiation position.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications, within the scope of the gist of the present invention described in the claims, It can be changed.

It is a figure for demonstrating the outline of the annealing process to a workpiece. It is a figure which shows an example of the processing target object thermally deformed. It is a figure which shows the example of 1 structure of the laser processing apparatus in this invention. It is a figure which shows the correspondence of the process conditions accumulate | stored and a correction pattern. It is a flowchart which shows an example of the production | generation process procedure of the correction pattern in this invention. It is a flowchart which shows an example of the laser processing procedure in this invention. It is a figure which shows the example of installation of the alignment mark. It is a figure which shows an example of a correction pattern.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 32, 41 Processing object 12, 42 Alignment mark 20 Laser processing apparatus 21 Trigger generation means 22 Laser oscillator 23 Mask 24 Imaging lens 25 Processing stage 26 Processing stage drive means 27 Position detection means 28 Imaging means 29 Thickness measurement means 30 storage means 31 control means 43 line alignment mark

Claims (10)

In a laser processing apparatus that performs laser processing on a predetermined region by irradiating a plurality of positions of a processing object with laser light,
A processing stage on which the processing object is placed;
A processing stage driving means for moving the processing stage to the plurality of positions;
Position detecting means for detecting the position of the processing stage;
A thickness measuring means for measuring the thickness of the workpiece;
Control means for obtaining a specific correction pattern from correction patterns for a plurality of processing conditions accumulated in advance based on the processing conditions for the processing object, and performing control to correct the irradiation position of the laser beam by the acquired correction pattern And a laser processing apparatus. The control means includes
The specific correction pattern is acquired from the correction patterns for a plurality of processing conditions accumulated in advance using the thickness of the processing object obtained by the thickness measuring unit as the processing condition. Laser processing equipment. The control means includes
Specify from a correction pattern for a plurality of pre-stored processing conditions as at least one of the laser beam type, pulse energy, material to be processed, volume, mask slit shape, processing path, and processing speed The laser processing apparatus according to claim 1, wherein the correction pattern is acquired. Having imaging means for photographing the alignment mark formed on the workpiece;
The control means includes
The amount of positional deviation is measured based on a theoretical value as an irradiation position of laser light set in advance and an actual value obtained from image data photographed by the imaging means after laser processing, and from the measured amount of positional deviation The laser processing apparatus according to claim 1, wherein a correction pattern is generated. The control means includes
4. The laser processing apparatus according to claim 1, wherein at least one correction pattern is generated among the entire predetermined area, each predetermined moving area, and each irradiation position. 5. In a laser processing method of performing laser processing on a predetermined region by irradiating a plurality of positions of a processing object with laser light,
An irradiation step of irradiating the plurality of positions with laser light based on a theoretical value as a preset irradiation position of the laser light;
An acquisition step of acquiring a position actually irradiated by the irradiation step;
A deviation amount measuring step for measuring a deviation amount between the theoretical value and the actual value obtained by the obtaining step;
A correction pattern generation step for generating a correction pattern from the shift amount obtained by the shift amount measurement step;
And a storage step of storing the correction pattern obtained in the correction pattern generation step in correspondence with the processing conditions. A thickness measuring step for measuring the thickness of the workpiece,
The laser processing method according to claim 6, wherein the storing step stores the thickness measured in the thickness measuring step in correspondence with the correction pattern using the thickness measured as the processing condition. The correction pattern generation step includes
8. The laser processing method according to claim 6, wherein at least one correction pattern is generated among the entire predetermined region, every predetermined moving region, and each irradiation position. 9. A search step for searching for a correction pattern corresponding to the same processing condition as a processing condition at the time of a new processing from the accumulated data accumulated by the accumulation step;
A correction step of correcting the irradiation position of the laser beam by the correction pattern obtained by the search step;
The laser processing method according to claim 6, further comprising a processing step of processing the workpiece by irradiating a laser beam to the irradiation position corrected by the correcting step. . The deviation measuring step includes
Scan processing is performed using a mask provided with a hole for attaching a laser irradiation trace for displacement confirmation to an alignment mark provided corresponding to a preset irradiation position of the processing object by the irradiation step, The laser processing method according to any one of claims 6 to 9, wherein a deviation amount is measured from the alignment mark and the laser irradiation trace image taken in the acquisition step.

Images