JP2002331379A - Laser beam machining method and laser beam machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam machining method capable of conducting the machining without displacement of a laser irradiation position. SOLUTION: Recognition coordinates, being the coordinates of first and second alignment marks 14A, 14B recognized by recognizing devices 26, 28, and reference coordinates 14A, 14B, being the coordinates of the first and second alignment marks recognized by recognizing devices 26, 28 when a board 11 is arranged on the nondisplacing position on a XY table 15 previously measured, are compared. On the basis of this comparison, the displacement on an orthogonal axes containing the XY table against the XY table of the board 11, and the displacement in the rotating direction around the axis lines orthogonal to the orthogonal axes are calculated. The XY table 15 and a laser irradiation optical system 18 are operated so as to correct these displacements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing method such as laser marking for marking characters, symbols, and the like on a glass substrate, and a laser processing apparatus.

[0002]

2. Description of the Related Art Conventionally, when marking characters, symbols, and the like on a substrate such as a glass substrate by laser processing, the following substrate position regulation has been performed in order to position a laser irradiation position.

First, as shown by a solid line in FIG. 9, a substrate 2 is placed on a stage 1. In this state, the substrate 2
Is shifted from the state of being positioned with respect to the stage 1 (indicated by a dotted line in FIG. 9), and the marking position 2
a is also shifted. Therefore, the substrate 2 is rotated by rotatable regulating rollers 3A and 3B that linearly move in the X-axis direction and the Y-axis direction.
Is moved on the stage 1, and these regulating rollers 3A, 3A
The position of the substrate 2 is regulated by B and the regulating member 4 fixed on the stage 1. After this position regulation, the entire stage 1 is moved to a designated position, and marking by laser processing is executed.

[0004]

However, there are the following problems in board position regulation by the board regulation mechanism including the regulation rollers 3A and 3B and the regulation member 4. First, the provision of the substrate regulating mechanism complicates the structure of the laser processing apparatus. In addition, the tact time of laser processing is reduced by the time required for the board regulation. Furthermore, even if the substrate position is regulated by the substrate regulating mechanism, it is difficult to completely eliminate the slight displacement of the substrate position and the minute displacement of the character string caused by the displacement.

Accordingly, an object of the present invention is to provide a laser processing method and a laser processing apparatus capable of performing processing without deviation of a laser irradiation position without using a substrate regulating mechanism.

[0006]

According to a first aspect of the present invention, a substrate provided with first and second alignment marks is placed on an XY table, and the first and second alignment marks are provided. When the alignment mark is recognized by the recognition device, and the recognition coordinates, which are the coordinates of the first and second alignment marks recognized by the recognition device, and the substrate are arranged on the XY table measured in advance at a position without displacement. Comparing the reference coordinates, which are the coordinates of the first and second alignment marks recognized by the recognition device, with the displacement of the substrate on the orthogonal axis including the XY table with respect to the XY table based on the comparison. Calculating the shift in the rotation direction about the axis orthogonal to the orthogonal axis, correcting the shift in the orthogonal axis direction by moving the XY table, Deviation of the rotational direction is corrected by the operation of the laser irradiation optical system, to provide a laser processing method for performing processing by laser irradiation on the substrate.

[0007] The above-mentioned processing includes, for example, laser marking.

In the laser processing method of the first invention, the displacement of the substrate on the orthogonal axis including the XY table and the displacement in the rotational direction about an axis orthogonal to the orthogonal axis are determined by the first and second alignments. It is calculated based on a comparison between the recognition coordinates of the mark and the reference coordinates, and the XY coordinates are corrected so as to correct these deviations.
Since the table and the laser irradiation optical system are operated, it is not necessary to regulate the substrate by the substrate regulating mechanism, and the tact of laser processing is improved. Further, since the XY table and the laser irradiation optical system are operated so as to correct the displacement of the substrate calculated based on the recognition results of the first and second alignment marks, a slight displacement of the substrate position and the A small displacement of the character string can be eliminated with high precision.

A second invention is a laser processing apparatus for processing a substrate provided with first and second alignment marks by laser irradiation from a laser irradiation optical system, wherein the XY table on which the substrate is mounted is provided. And a recognition device for recognizing the substrate on the XY table, and a control unit for controlling the laser irradiation optical system and the XY table, wherein the control unit is configured to control the first and second recognition by the recognition device. Recognition coordinates, which are coordinates of alignment marks, and reference coordinates, which are coordinates of the first and second alignment marks recognized by the recognition device when the substrate is placed on a previously measured XY table at a position without displacement. And a displacement of the substrate with respect to the XY table on the orthogonal axis including the XY table, based on the comparison, Calculating the displacement in the rotation direction about the axis, moving the XY table to correct the displacement in the orthogonal axis direction, and operating the laser irradiation optical system to correct the displacement in the rotation direction. A laser processing device is provided.

In the laser processing apparatus according to the second aspect of the present invention, since there is no need to control the substrate, the tact of laser processing is improved. Further, a minute displacement of the substrate position and a minute displacement of the character string caused by the displacement can be eliminated with high accuracy. further,
Since there is no need to provide a substrate regulating mechanism, the structure of the apparatus can be simplified.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a laser marking apparatus for carrying out a laser processing method according to an embodiment of the present invention comprises an XY table 15 on which a glass substrate 11 to be processed is placed. Have. The XY table 15 has an X-axis ball screw 17A and a Y-axis ball screw 1 which are rotationally driven by servo motors 16A and 16B, respectively.
7B moves in the horizontal plane. XY table 1
Above 5 is a laser unit (laser irradiation optical system) 1
8 are provided. The laser unit 18 includes a laser transmitter 19, a reflection half mirror 21, an fθ lens 22,
And a galvanomirror 23. Laser transmitter 1
The laser beam emitted by the laser beam 9 is reflected by the reflection half mirror 21 and fθ
The light enters the galvanomirror 23 via the lens 22 and is polarized by the galvanomirror 23 in two directions orthogonal to each other. Further, a recognition camera 26 for recognizing the glass substrate 11 and the laser irradiation point 24 on the XY table 15 is provided above the XY table 15.

A main controller (control unit) 27 controls the laser transmitter 19, the servomotors 16A and 16B, and the galvanometer mirror 23. In addition, recognition camera 2
6 is input to the main controller 27 via the recognition unit 28. The recognition camera 26 and the recognition unit 28 constitute a recognition device according to the present invention. The main controller 27 executes determination of reference coordinates and a reference movement amount described later, determination of recognition coordinates, calculation of a correction amount, and the like based on the input image, and further performs laser marking based on the calculation result of the correction amount. Execute.

As shown in FIG. 2, a rectangular glass substrate 11 is provided.
A plurality of (four in the present embodiment) liquid crystal chips 12 are mounted on each of them, and a marking position 13 is set for each liquid crystal chip 12. In addition, first and second alignment marks 14A and 14B are marked in advance at corners forming a pair of diagonal lines of the glass substrate 11.

In this embodiment, the XY table 15
, The X-axis and Y-axis of the galvanomirror 23, and the X-axis and Y-axis of the glass substrate 11 itself are all set in the same direction.
The alignment marks 14A and 14B are marked at the same position on all the glass substrates 11.

Next, a method of laser marking by the above laser marking apparatus will be described. In FIG. 3, when the glass substrate 11 is simply placed on the XY table 15 as shown by the solid line, that is, when the substrate position is not regulated, the regular position of the glass substrate 11 shown by the dotted line (when the substrate position is regulated Position after position regulation). More specifically, the positional deviation includes positional deviations ΔX and ΔY in the X-axis direction and the Y-axis direction, and rotational deviation (a rotational deviation about an axis orthogonal to the X-axis and the Y-axis). There is θ. In the example of FIG. 3, the centroid G1 of the glass substrate 11 in plan view moves by ΔX and ΔY with respect to the normal position (dotted line), and moves to G2 (dashed line).
There is a deviation of the rotation angle θ around 2. The sum of the displacement in the X-axis and Y-axis directions and the displacement in the rotation direction is the displacement of the alignment marks 14A and 14B.

In this embodiment, the alignment mark 14 is used.
By recognizing A and 14B, X of the glass substrate 11 is
Without restricting the position of the Y table 15, XY
The displacement of the marking position 13 is corrected by the movement of the table 15 and the operation of the galvanomirror 23. In order to execute this correction, it is necessary to measure the coordinates (reference coordinates) of the alignment marks 14A and 14B when the glass substrate 11 has no displacement. Hereinafter, the determination of the reference coordinates will be described with reference to the flowchart of FIG.

First, in step S41, the glass substrate 11 is placed on the XY table 15 at the initial position at a position where there is no displacement. Next, as shown by an arrow A in FIG. 5, the XY table 1 is moved by the amount of movement (a, b) corresponding to the centroid G of the glass substrate 11 and the alignment mark 14A.
5 is moved, and the alignment mark 14A is photographed by the recognition camera 26. The image of the alignment mark 14A is transmitted to the recognition unit 28, and the recognition unit 2
The coordinates (Xa, Ya) on the coordinate axes of 8 are determined. These coordinates (Xa, Ya) are the alignment mark 1
4A are reference coordinates. Note that the above movement amounts (a, b),
That is, the reference movement amount may be any value as long as the alignment mark 14A is within the field of view of the recognition camera 26.

Similarly, in step S42, the reference coordinates (Xb, Y) are set for the second alignment mark 14B.
b) and the reference movement amount (c, d) are determined. That is, as shown by an arrow B in FIG. 5, after moving the XY table 15 by the reference movement amount (c, d), the second alignment mark 14B is photographed by the recognition camera 26, and the coordinate axes of the recognition unit 28 are The coordinates of the alignment mark 14B are determined.

Finally, the reference coordinates (Xa, Ya) and (Xa) of the first and second alignment marks 14A and 14B are set.
b, Yb), and the first and second reference movement amounts (a,
The main controller 27 stores b) and (c, d).

Next, laser marking will be described with reference to the flowchart of FIG. First, step S6
In 1, the glass substrate 11 is placed without positioning on the XY table 15 at the initial position.

Next, in step S62, the XY table 15 is moved from the initial position by the reference movement amount (a, b), and the first alignment mark 14A is photographed by the recognition camera 26. First alignment mark 14
The image of A is transmitted to the recognition unit 28, and the coordinates (Xa ′, Ya ′) on the coordinate axes of the recognition unit 28 are determined. These coordinates (Xa ′, Ya ′) are the recognition coordinates of the first alignment mark 14A.

Similarly, in step S63, the recognition coordinates of the second alignment mark 14B are determined. That is, the XY table 15 is moved from the initial position by the reference movement amount (b, c), the second alignment mark 14B is photographed by the recognition camera 26, and the recognition unit 2
8 (Xb ′, Y)
b ′) is determined.

As shown in FIG. 7, reference coordinates (Xa, Y) of the first and second alignment marks 14A, 14B are used.
a), (Xb, Yb) and the recognition coordinates (Xa ′, Y
a ′) and (Xb ′, Yb ′) have the relationship of the following equation (1). In this equation (1), dXa and dXb indicate deviations in the X-axis direction of the recognition coordinates of the first and second alignment marks 14A and 14B with respect to the reference coordinates. Also, dYa and dYb indicate the deviation in the Y-axis direction of the recognition coordinates of the first and second alignment marks 14A and 14B with respect to the reference coordinates.

[0024]

First and second alignment marks 14
Reference coordinates of A and 14B (Xa, Ya), (Xb, Yb)
And recognition coordinates (Xa ', Ya'), (Xb ', Yb')
Is transmitted to the main controller 27, and is transmitted to step S6.
In step 4, the main roller and the roller 27 calculate the correction amount.

As described above, the X-axis and Y-axis of the glass
Since the sum of the displacement in the axial direction and the displacement in the rotation direction is the displacement of the alignment marks 14A and 14B, the recognition coordinates (Xa ', Y
a ′), (Xb ′, Yb ′) and the deviations ΔX, ΔY of the glass substrate 11 in the X-axis and Y-axis directions, and the deviation angle θ in the rotation direction, are given by the following equations (2), ( The relationship of 3) is established.

[0027]

[0028]

By substituting equation (1) into equations (2) and (3), the following equations (4) and (5) are obtained.

[0030]

[0031]

From the equations (4) and (5), the following equations (6), (7), (8) and (9) are obtained.

[0033]

[0034]

[0035]

[0036]

As is apparent from the above equations (6) to (9), the first and second alignment marks 14A, 14A
From the reference coordinates of B and the difference between the reference coordinates and the recognized coordinates, deviations ΔX and ΔY in the X-axis and Y-axis directions of the glass substrate 11 with respect to the XY table 15 of the glass substrate 11 and a deviation θ in the rotation direction are calculated. The main controller 27 stores the calculated deviations ΔX, ΔY, θ.

Next, in step S65, the XY table 15 moves to the marking position. Specifically, the XY table 15 is moved in the X-axis direction and the Y-axis direction so as to correct the deviation in the X-axis and Y-axis directions. This XY
By moving the table 15, the start position of the laser marking is corrected.

Thereafter, in step S66, laser marking is performed on the glass substrate 11. At this time, the rotation of the galvanomirror 23 adjusts the rotation angle of the character string to be marked by the angle calculated by the equation (8). For example, in the example of FIG. 8, the rotational direction deviation θ of the first point (writing) of the second character “B” to be marked at the marking position 13 is corrected.

In the laser marking method and apparatus according to the present embodiment, the structure of the apparatus can be simplified since a substrate regulating mechanism for positioning the glass substrate 11 with respect to the XY table 15 is unnecessary. In addition, since the operation of regulating the substrate is not required, the tact time can be improved.
Further, since the marking position is corrected based on the recognition result of the first and second alignment marks 14A and 14B of the glass substrate 11, a slight displacement of the substrate position with respect to the XY table 15 and a minute character string caused by the displacement are caused. The displacement can be corrected with high accuracy.

The present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above embodiment, the directions of the rectangular coordinates of the stage, the galvanomirror, and the substrate are all the same, but the present invention is applied by performing coordinate conversion even when the directions of these rectangular coordinate systems do not match. Can be.

The optical system for irradiating the laser is not limited to the combination of the fθ lens and the galvanomirror, but may be any as long as it can change the irradiation position of the laser light emitted from the laser light source in at least two directions. The present invention is not limited to the laser marking technology, but can be applied to other laser processing technologies such as a substrate drilling process.

[0043]

As is apparent from the above description, in the laser processing method and the laser processing apparatus of the present invention, the XY
A shift on the orthogonal axis including the table and a shift in a rotational direction about an axis orthogonal to the orthogonal axis are calculated based on a comparison between the recognized coordinates of the first and second alignment marks and the reference coordinates, and The XY table and the laser irradiation optical system are operated so as to correct the deviation. Therefore, there is no need to provide a substrate regulating mechanism, and the structure of the laser processing apparatus can be simplified. In addition, since there is no need to regulate the substrate, the tact time of laser processing is improved. Further, since the XY table and the laser irradiation optical system are operated so as to correct the displacement of the substrate calculated based on the recognition results of the first and second alignment marks, a slight displacement of the substrate position and the resulting displacement are caused. A slight displacement of a character string can be resolved with high precision.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a laser marking device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a glass substrate.

FIG. 3 is a schematic plan view for explaining displacement of a glass substrate with respect to an XY table.

FIG. 4 is a flowchart for explaining determination of reference coordinates and a reference movement amount.

FIG. 5 is a schematic plan view for explaining a reference movement amount.

FIG. 6 is a flowchart for explaining laser marking.

FIG. 7 is a diagram for explaining a relationship between reference coordinates and recognition coordinates.

FIG. 8 is a plan view showing an example of correction of a rotational deviation θ.

FIG. 9 is a schematic plan view showing an example of a substrate regulating mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Glass substrate 12 Liquid crystal chip 13 Marking position 14A, 14B Alignment mark 15 XY table 16A, 16B Servo motor 17A, 17B Ball screw 18 Laser unit 19 Laser transmitter 21 Reflection half mirror 22 fθ lens 23 Galvano mirror 24 Laser irradiation point 26 Recognition camera 27 Main controller 28 Recognition unit

Claims (3)

[Claims] 1. A substrate provided with first and second alignment marks is placed on an XY table, the first and second alignment marks are recognized by a recognition device, and the first and second alignment marks are recognized by the recognition device. Recognition coordinates, which are the coordinates of the first and second alignment marks, and the coordinates of the first and second alignment marks recognized by the recognition device when the substrate is placed on the XY table measured in advance without any displacement. And comparing the coordinates with the reference coordinates, and based on the comparison,
Calculating a shift on an orthogonal axis including the XY table and a shift in a rotational direction about an axis orthogonal to the orthogonal axis, correcting the shift in the orthogonal axis direction by moving the XY table, and A laser processing method of correcting the displacement by the operation of a laser irradiation optical system and processing the substrate by laser irradiation. 2. The method according to claim 1, wherein the processing is laser marking. 3. A laser processing apparatus for processing a substrate provided with first and second alignment marks by laser irradiation from a laser irradiation optical system, comprising: an XY table on which the substrate is placed; A recognition device for recognizing the substrate on the table; and a control unit for controlling the laser irradiation optical system and the XY table, wherein the control unit controls the coordinates of the first and second alignment marks recognized by the recognition device. Is compared with reference coordinates, which are the coordinates of the first and second alignment marks recognized by the recognition device when the substrate is arranged at a position without displacement on the XY table measured in advance. XY of the substrate based on this comparison
The displacement of the XY table with respect to the table on the orthogonal axis including the XY table and the displacement in the rotational direction about the axis orthogonal to the orthogonal axis are calculated, and the movement of the XY table is corrected so as to correct the displacement in the orthogonal axis direction. A laser processing apparatus that moves and operates a laser irradiation optical system so as to correct the above-described deviation in the rotation direction.