JPH09141459A - Laser machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform laser machining so that a specific machined shape is obtained by measuring the position interval between two alignment marks that a mark detection part detects successively, comparing it with previously set and stored drawing size, and generating a correction output command signal and controlling a driving mechanism. SOLUTION: A distance measurement part measures the actual interval between the two alignment marks 11 detected successively by a CCD camera 8 for fine adjustment. A motion controller finds the ratio of the measured interval and the previously set and stored drawing size of the same interval on a drawing and generates the correction output command signal by multiplying the drawing size by a correction coefficient obtained from the found ratio. In response to this correction output command signal, the driving mechanism 4 is controlled. Even if respective dimensions of the work 2 vary as the ambient temperature varies, set machining values vary in the same way corresponding to the size variation, so an XY table 3 can be moved to an accurate machining position at any time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus, and more particularly, to detecting a positional interval between two alignment marks provided on a workpiece (workpiece) and detecting the ambient temperature of the workpiece from the detected positional interval. Find the dimensional changes that accompany changes,
After that, the present invention relates to a laser processing apparatus that performs laser processing of a workpiece in consideration of the obtained dimensional change.

[0002]

2. Description of the Related Art Generally, when a laser beam is used to machine an object to be machined, the position of the object to be machined and the laser beam machine to be machined before the laser machining of the object to be machined. The workpiece is moved to the optimum position for laser processing, that is, the alignment adjustment of the workpiece is performed so that the projection position of the laser light projected from the laser light projection unit matches.

The already known alignment adjustment of a work piece is performed by a work table including an alignment bar or the like on a work piece mounting table or a work piece mounting plate used for laser processing the work piece. An object position restricting member is provided, and when the workpiece is mounted on a mounting table, a mounting plate, or the like, the optimum disposition position is determined by the workpiece position restricting member such as an alignment bar.

Then, after the alignment adjustment of the workpiece, the laser processing apparatus responds to the set processing value preset and stored in the motion controller.
Vertical and horizontal movable table (XY
Each time the table is moved in the vertical and horizontal directions and the work piece is moved, the laser beam is intermittently projected onto the work piece from the laser light irradiation section, whereby the work piece has a predetermined processing shape. Laser processing is performed so that

[0005]

By the way, in the known laser processing apparatus, the XY table is sequentially moved in the vertical and horizontal directions by a predetermined distance in accordance with the set processing value set and stored in advance in the motion controller to process the workpiece. Every time an object is moved, a laser beam is projected intermittently from the laser beam projection unit onto the workpiece, and the prescribed laser processing is automatically performed. When a dimensional change occurs in the work piece, for example, when the work piece is a color filter used in a liquid crystal display unit and the color filter is subjected to high precision fine laser processing, a change in ambient temperature, etc. It becomes impossible to ignore the dimensional change of each part of the color filter due to.

That is, in the known laser processing apparatus, when the dimensional change of the work piece occurs due to the change of the ambient temperature or the like, the XY table is sequentially set according to the set processing value which is set and stored in advance in some cases. There is a problem in that even if the workpiece is moved in the vertical and horizontal directions by a predetermined distance, the laser processing cannot be performed so that the workpiece has a predetermined processing shape.

The present invention solves the above problems,
An object of the present invention is to provide a laser processing apparatus that performs laser processing using a set processing value in consideration of the dimensional change even when the dimensional change of a workpiece occurs due to a change in ambient temperature. .

[0008]

In order to achieve the above-mentioned object, the present invention is designed so that a work piece is placed and X is driven by a drive mechanism.
XY that can slide freely in the (horizontal axis) direction and the Y (vertical axis) direction
A table, a laser beam projection unit that projects a laser beam derived from a laser oscillator onto the workpiece through an optical system to perform laser processing on the workpiece, and two or more alignments provided on the workpiece. A mark detection unit that detects the position of a mark, a distance measurement unit that measures the movement distance of the XY table in the X direction and the Y direction, and a controller unit that sets and stores drawing dimensions of each part of the workpiece. And a driver unit that controls the drive mechanism in response to an output command signal from the controller unit, wherein the distance measuring unit measures a position interval between two alignment marks continuously detected by the mark detecting unit, The controller unit compares the measured position interval with a drawing dimension of the same position interval that is preset and stored, and a correction factor obtained by the comparison. The generating a corrected output command signal multiplied by the drawing dimensions, said driver unit comprises means for controlling the drive mechanism in response to the corrected output command signal.

In the above means, the distance measuring unit measures the actual distance between the two alignment marks continuously detected by the mark detecting unit, and the controller unit has the same actual distance as the measured actual distance. Of the drawing dimension, and the drawing dimension is multiplied by the correction coefficient obtained from the calculated ratio to generate a correction output command signal, and the driver unit controls the drive mechanism in response to the correction output command signal. Even if the dimensions of each part of the workpiece change due to ambient temperature fluctuations, etc., the set machining value changes in the same way in response to the dimensional change, so that the XY table can always be used for accurate machining position. It is possible to move the laser beam up to, and it is possible to perform laser processing so that the workpiece has a predetermined processing shape.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a configuration diagram showing an example of the structure of a laser processing apparatus according to the present invention, FIG. 1 (a) is a side view thereof, and FIG. 1 (b) is a top view thereof.

As shown in FIGS. 1 (a) and 1 (b), the laser processing apparatus 1 mainly comprises a workpiece 2 to be processed.
An XY table 3 on which the workpiece 2 is placed and slidable in the vertical and horizontal directions, a drive mechanism 4 including a linear motor for sliding the XY table 3, a laser oscillator 5 for generating a laser beam, and 2 Built-in two condenser lenses 6 (1), 6 (2), an optical shutter (not shown), a reflecting mirror (not shown), etc., and intermittently projects the laser light generated by the laser oscillator 5 onto the workpiece 2. An optical system 6, a coarse adjustment CCD camera 7, a fine adjustment CCD camera 8, a lens barrel 9 containing a reflecting mirror (not shown) and the like, and a surface plate 10 with an anti-vibration foot 10 (1). It consists of

In this case, the laser oscillator 5 and the optical system 6
Is a laser light projection unit, and a coarse adjustment CCD camera 7
The fine adjustment CCD camera 8 and the lens barrel 9 constitute a mark detection unit. The workpiece 2 is, for example, a color filter used in a liquid crystal display unit, and one alignment mark 11 (only one is shown) is provided at each end of the color filter. The drive mechanism 4 is a lateral (X-axis) direction linear motor yoke 4X.
(1) and a pair of lateral (X-axis) direction rails 4X (2) and 2
Two vertical (Y-axis) direction linear motor yokes 4Y (1) and 2
It is provided with a pair of vertical (Y-axis) direction rails 4Y (2).

The XY table 3 is appropriately moved in the lateral (X-axis) direction and the vertical (Y-axis) direction by the drive of the drive mechanism 4, and the workpiece 2 placed on the XY table 3 is also XY. As the table 3 moves, the table 3 moves in the horizontal (X axis) direction and the vertical (Y axis) direction. The laser light projection unit projects the laser light generated by the laser oscillator 5 onto the workpiece 2 via the optical system 6 to perform laser processing on the workpiece 2. In this case, the laser beam projected onto the workpiece 2 is the optical system 6
Is interrupted by an optical shutter (not shown) built into the
Laser light is intermittently projected onto the workpiece 2. The mark detection unit determines the position of the alignment mark 11 provided on the workpiece 2, for example, the color filter, from the lens barrel 1
0 through coarse adjustment CCD camera 7 and fine adjustment CCD
The image is picked up by the camera 8 and a detection output indicating the position coordinates is generated. In this case, each alignment mark 11
On the other hand, first, position detection is performed by the coarse adjustment CCD camera 7, and then position detection is performed by the fine adjustment CCD camera 8.

Next, FIG. 2 is a configuration diagram showing an alignment mark detecting portion in the laser processing apparatus shown in FIG. 1, FIG. 2 (a) is a perspective view thereof, and FIG. 2 (b) is a sectional view thereof. The same components as those shown in FIGS. 1A and 1B are designated by the same reference numerals.

As shown in FIGS. 2 (a) and 2 (b), the lens barrel 9 has two reflecting mirrors 9 (1) and 9 (2) arranged in tandem therein. , 9 (2), a coarse adjustment CCD camera 7 and a fine adjustment CCD camera 8 are arranged respectively. The position adjusting plate 1 is provided at the tip of the lens barrel 9.
2 is arranged, the objective lens 13 is attached to the position adjusting plate 12, and the height (Z) direction position adjusting motor 14 is connected. An optical fiber 9 (3) for supplying illumination light is connected to the base of the lens barrel 9, and a height direction position adjusting motor 14 is attached to the side surface of the lens barrel 9.

Then, by driving the driving mechanism 4, the XY table 3 is appropriately moved so that the object lens 13 faces the workpiece 2, for example, the alignment mark 11 provided on the color filter used in the liquid crystal display section. At the same time, after adjusting the height direction position adjusting motor 14 to adjust the height of the objective lens 13 with respect to the alignment mark 11, the illumination light supplied from the optical fiber 9 (3) is changed to
The light is projected onto the alignment mark 11 through the two reflecting mirrors 9 (1) and 9 (2) in the lens barrel 9 and the objective lens 13 attached to the position adjusting plate 12. At this time, the image of the alignment mark 11 illuminated by the illumination light is passed through the objective lens 13 and the two reflecting mirrors 9 (1) and 9 (2) to the coarse adjustment CCD camera 7, and the objective lens 13 and the reflecting mirror 9 ( 2) is transmitted to the CCD camera 8 for fine adjustment through the CCD camera 7 for coarse adjustment and the CC for fine adjustment.
It is projected by the D camera 8.

Here, FIG. 3 is a block diagram showing the main components of the control system of the laser processing apparatus according to the present invention, and here again, the components shown in FIGS. 1 (a) and 1 (b). The same components as those in are denoted by the same reference numerals.

As shown in FIG. 3, scales (not shown) are provided at equal intervals on the lateral (X-axis) side surface of the XY table 3, and the lateral linear encoder 15 is opposed to the scales.
(X) is arranged, and similarly, the vertical direction of the XY table 3 (Y
Scales (not shown) are attached at even intervals on the (axis) direction side,
Vertical linear encoder 15 (Y) facing the scale
Is arranged. In this case, when the XY table 3 moves in the horizontal direction, the horizontal linear encoder 15 (X) counts the number of movements of the scale attached to the lateral side surface, and the encoder output signal corresponding to the counted number, that is, XY. A detection output signal indicating the horizontal movement distance of the table 3 is generated. Similarly, when the XY table 3 moves in the vertical direction, the vertical direction linear encoder 15 (Y) counts the number of movements of the scale attached to the vertical side surface, and an encoder output signal corresponding to the counted number, that is, A detection output signal indicating the vertical movement distance of the XY table 3 is generated. The horizontal linear encoder 15 (X) and the vertical linear encoder 15 (Y) form a distance measuring unit. The motion controller 16 stores in advance a motion program that causes laser processing to be executed in a predetermined order, dimensions of each part of the workpiece 2, for example, an arrangement interval of two alignment marks, and the like.
(1) and the comparison unit 16 (2) are built in, and the horizontal linear encoder 15 (X) and the vertical linear encoder 15
The detection output signal from (Y) is received. The servo driver 18 controls and drives the drive mechanism 4 including a linear motor to move the XY table 3, and operates in response to a command signal from the motion controller 16.

Next, FIG. 4 is a flow chart showing an operation process when carrying out alignment adjustment and subsequent laser processing in the laser processing apparatus of the present invention.

Each operation of alignment adjustment and subsequent laser processing performed by the laser processing apparatus of the present invention will be described with reference to the flowchart shown in FIG.

First, in step S1, each part of the laser processing apparatus 1 is initialized.

Next, in step S2, the origin position coordinates are measured by image processing to find the correlation between the physical origin position coordinates in the XY table 3 and the origin position coordinates in the alignment adjustment optical system.

In step S3, it is set whether the laser processing apparatus 1 is automatically operated or not. When the automatic operation is set (Y), the process proceeds to the next step S4, and when the automatic operation is not set (N), the series of flowcharts is ended.

Next, in step S4, the drive mechanism 4 including a linear motor is driven to move the XY table 3 to a position (workload position) where the workpiece 2 can be placed.

Next, in step S5, the workpiece 2 is placed (workload) on the XY table 3.

Subsequently, in step S6, the driving mechanism 4 is driven to drive one of the ones (first) provided on the workpiece 2.
The XY table 3 is moved so that the alignment mark 11 of (1) substantially coincides with the position of the objective lens 13 below the lens barrel 9 which constitutes the mark detection unit.

Thereafter, in step S7, the first alignment mark 11 is projected by the coarse adjustment CCD camera 7 while being illuminated by the illumination light from the optical fiber 9 (3). Rough adjustment using the first alignment mark 11 is performed by measuring the position of the center of gravity of the image.

Next, in step S8, the drive mechanism 4 is driven again, and the other one (second) alignment mark 11 provided on the workpiece 2 is also located below the lens barrel 9. X so that it almost coincides with the position of the lens 13.
Y table 3 is transferred.

Then, in step S9, the second alignment mark 11 is projected again by the coarse adjustment CCD camera 7 while the second alignment mark 11 is illuminated by the illumination light from the optical fiber 9 (3). The coarse adjustment using the second alignment mark 11 is performed by measuring the position of the center of gravity of the image.

Here, in step S10, the image processing condition of the laser processing apparatus 1 is changed to a condition different from the previous conditions. The new image processing condition is that the intensity of the illumination light from the optical fiber 9 (3) is increased, the height direction position adjusting motor 14 is driven, and the distance from the surface of the workpiece 2 to the objective lens 13 is predetermined. Adjust to the value of
It is changed so as to execute precision image processing using the fine adjustment CCD camera 8.

Next, in step S11, the drive mechanism 4 is driven, and the second alignment mark 11 provided on the workpiece 2 is located below the lens barrel 9 of the objective lens 13.
The XY table 3 is slightly moved so as to match the position of.

Then, in step S12, the second alignment mark 11 is projected by the fine adjustment CCD camera 8 while being illuminated by the illumination light from the optical fiber 9 (3). By measuring the position of the center of gravity of the image, fine adjustment using the second alignment mark 11 is performed.

Subsequently, in step S13, the drive mechanism 4 is driven again, and the first alignment mark 11 provided on the workpiece 2 coincides with the position of the objective lens 13 below the lens barrel 9. Thus, the XY table 3 is moved.

Next, in step S14, the first alignment mark 11 is projected by the coarse adjustment CCD camera 7 while being illuminated by the illumination light from the optical fiber 9 (3). By measuring the barycentric position of the image, fine adjustment using the first alignment mark 11 is performed.

After these adjustments have been made, step S1
5, based on the coordinate position obtained by the fine adjustment using the first alignment mark 11 and the coordinate position obtained by the fine adjustment using the second alignment mark 11, the orthogonal coordinate ( XY system) and XY
The angle deviation θ and the positional deviations Δx and Δy from the physical rectangular coordinate (XY coordinate) system in the table 3 are calculated.

Thereafter, in step S16, the drive mechanism 4 and the angle adjusting mechanism (not shown) are driven,
The XY table 3 is slightly rotated and slightly moved so as to eliminate the above-mentioned angular deviation θ and positional deviations Δx and Δy.

Next, in step S17, the laser processing apparatus 1 corrects the angular deviation θ due to the rotation of the XY table 3 performed in step S16, and the XY table 3 is corrected.
It is determined whether or not the angular deviation θ and the positional deviations Δx and Δy have been corrected by correcting the positional deviations Δx and Δy due to the movement of. Then, the angular deviation θ and the positional deviation Δ
When it is determined that x and Δy have been corrected (Y), the process proceeds to the next step S18, while when it is determined that these angular deviation θ and positional deviations Δx and Δy have not been completely corrected (N), The process returns to step S11 described above, and the processes after step S11 are repeatedly executed.

At the subsequent step S18, when the fine adjustment using the second alignment mark 11 is changed to the fine adjustment using the first alignment mark 11, the motion controller 16 causes the lateral linear encoder 1 to move.
Based on the detection output signals obtained by 5 (X) and the vertical direction linear encoder 15 (Y), the actual interval (actual size) between the first alignment mark 11 and the second alignment mark 11 is calculated.

Then, in step S19, the motion controller 16 causes the first alignment mark 1
The actual distance (actual size) between the first and second alignment marks 11 and the size (drawing size) of the first alignment mark 11 and the second alignment mark 11 on the drawing stored in the memory 16 (1). Comparing the ratio of 16 (2)
And the correction coefficient is set based on the calculation result.

Then, in step S20, the motion controller 16 corrects the motion program already stored in advance in the memory 16 (1) using the set correction coefficient K. At this time, the moving distance and the like of the XY table 3 included in the motion program are replaced with those in which the set correction coefficient K is added.

Here, in step S21, the laser processing apparatus 1 shifts the control system to the laser processing orthogonal coordinate system.

Thereafter, in step S22, the driving mechanism 4 is driven so that the processing start point of the workpiece 2 is the condenser lens 6.
The XY table 3 is moved so as to be directly below (1) and 6 (2).

Next, in step S23, the motion program in which the correction coefficient K stored in the memory 16 (1) of the motion controller 16 is added is sequentially read.

At this time, in step S24, the motion program with the correction coefficient K read from the motion controller 16 is supplied to the servo driver 17 as a correction output command signal, and the motion program with the correction coefficient K is executed. . When the motion program in which the correction coefficient K is added is executed, the driving mechanism 4 drives the XY table so that the processing points of the workpiece 2 are sequentially positioned directly below the condenser lenses 6 (1) and 6 (2). Three
Every time the XY table 3 is moved, the laser beam is intermittently projected from the laser beam projection unit to the processing point of the workpiece 2, and the laser processing corresponding to the motion program in which the correction coefficient K is added is performed. To be executed.

Next, in step S25, the laser processing apparatus 1 returns from the laser processing Cartesian coordinate system to the alignment Cartesian coordinate system.

Thereafter, in step S26, the drive mechanism 4 is driven to move to the position (workload unloading position) for taking out the workpiece 2 on the XY table 3, and then the workpiece on the XY table 3 is moved. Take out 2.

When it is necessary to perform laser processing on another workpiece 2 in the laser processing apparatus 1,
Returning to step S4 described above, the processes after step S4 are executed again. On the other hand, when it is not necessary to perform laser processing on another workpiece 2, the processing according to this series of flowcharts ends.

By the way, it is preferable that one alignment mark 11 is provided on each of the two sides of the workpiece 2 and that the shape thereof is a small round shape. However, the positions where the alignment marks 11 are provided do not have to be provided on both sides of the work piece 2 as long as they are spaced apart from each other, and the number thereof does not have to be two if it is plural. The shape of the alignment mark 11 is not limited to a small round shape, and may be a small triangle or a square.

The workpiece 2 is not limited to the color filter used in the liquid crystal display section, and it is needless to say that the workpiece 2 may be another one as long as it can perform high precision fine laser processing. is there.

Further, it is preferable that the distance measuring section uses linear encoders 15 (X) and 15 (Y).
As long as the moving distance of the Y table 3 can be accurately detected, another one may be used.

In addition to this, it is preferable to use a linear motor as the drive mechanism 4, but any other drive mechanism may be used as long as it can move the XY table 3 at high speed and with high precision.

[0053]

As described above in detail, according to the present invention, the distance measuring units 15 (X) and 15 (Y) are continued by the fine adjustment CCD camera 8 in the mark detecting units 7, 8 and 9. The actual distance between the two alignment marks 11 detected by the motion controller 16 is measured, and the motion controller 16 obtains the ratio between the measured actual distance and the drawing dimension of the same distance on the drawing which is preset and stored, and the calculated ratio is obtained. Correction factor K obtained from
The servo driver 17 controls the drive mechanism 4 in response to the correction output command signal by multiplying the dimension of the drawing with the correction output command signal. Even if the size of each part changes, the set machining value changes in the same way according to the dimensional change, so that it becomes possible to move the XY table 3 to an accurate machining position at all times, and There is an effect that laser processing can be performed so as to obtain a predetermined processing shape.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of a structure of a laser processing apparatus according to the present invention.

FIG. 2 is a configuration diagram showing an alignment mark detection unit in the laser processing apparatus shown in FIG.

FIG. 3 is a block configuration diagram showing main components of a control system of a laser processing apparatus according to the present invention.

FIG. 4 is a flowchart showing an operation process when carrying out alignment adjustment and subsequent laser processing in the laser processing apparatus of the present invention.

[Explanation of symbols]

 1 Laser Processing Device 2 Workpiece (Work) 3 XY Table 4 Drive Mechanism 4X (1) Horizontal Axis Linear Motor Yoke 4X (2) Horizontal Axis Rail 4Y (1) Vertical Axis Linear Motor Yoke 4Y (2) Vertical Axial rail 5 Laser oscillator 6 Optical system 6 (1), 6 (2) Condensing lens 7 CCD camera for coarse adjustment 8 CCD camera for fine adjustment 9 Lens barrel 9 (1), 9 (2) Reflector 9 (3 ) Optical fiber 10 Surface plate 10 (1) Anti-vibration foot 11 Alignment mark 12 Position adjustment plate 13 Objective lens 14 Height direction position adjustment motor 15 (X), 15 (Y) Linear encoder 16 Motion controller 16 (1) Memory 16 (2) Comparison section 17 Servo driver

Claims (5)

[Claims] 1. A work piece is placed and X is driven by a drive mechanism.
XY that can slide freely in the (horizontal axis) direction and the Y (vertical axis) direction
A table, a laser beam projection unit that projects a laser beam derived from a laser oscillator onto the workpiece through an optical system to perform laser processing on the workpiece, and two or more alignments provided on the workpiece. A mark detection unit that detects the position of a mark, a distance measurement unit that measures the movement distance of the XY table in the X direction and the Y direction, and a controller unit that sets and stores drawing dimensions of each part of the workpiece. And a driver unit that controls the drive mechanism in response to an output command signal from the controller unit, wherein the distance measuring unit measures a position interval between two alignment marks continuously detected by the mark detecting unit, The controller unit obtains a ratio between the measured position interval and a drawing dimension of the same position interval that is preset and stored, and calculates a correction coefficient obtained from the ratio. Generating a corrected output command signal multiplied by the serial Dimensional drawings, the driver unit, the correction laser processing apparatus and controls the drive mechanism in response to an output command signal. 2. The mark detection unit includes a coarse adjustment camera for the alignment mark and a fine adjustment camera after performing the coarse adjustment detection for the alignment mark. Laser processing equipment. 3. The laser processing apparatus according to claim 1, wherein the distance measuring unit has a linear encoder. 4. The laser processing apparatus according to claim 1, wherein the drive mechanism is a linear motor. 5. The laser processing apparatus according to claim 1, wherein the object to be processed is a color filter used in a liquid crystal display unit.