JP2000263261A - Laser processing apparatus and laser processing method using the apparatus - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a laser processing apparatus capable of efficiently performing laser processing at a high processing speed and high accuracy, and a method of performing laser processing using the laser processing apparatus. SOLUTION: In a laser processing apparatus having a laser oscillator 5, an optical system 6, a work table 1, and a displacement gauge 15, at the time of laser processing, a laser beam 67 based on three-dimensional data measured in advance on the surface of a portion to be processed. And a means for driving the worktable 1 so that the irradiation head including the imaging lens moves on the processing target portion along a predetermined scanning path.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a laser processing apparatus and a laser processing method for performing laser processing on a workpiece in a predetermined pattern.

[0002]

2. Description of the Related Art At present, various types of workpieces are processed by a laser beam using a laser processing apparatus because processing accuracy and processing speed can be improved.

[0003] For example, in the field of thin film precision processing,
In the step of trimming a color filter or a substrate used for a liquid crystal display device or a transparent electrode of a substrate or a display device, a laser processing device, particularly a YAG laser processing device, is used. Effects such as simplification of the manufacturing process and reduction of equipment cost are obtained.

[0004] For example, a processing apparatus for performing precision processing using a YAG laser is described in Japanese Patent Application Laid-Open No. 9-141481. The structure of the apparatus is generally described as shown in FIG. An optical system 6 including a laser oscillator 5, a mask for shaping the laser beam from the laser oscillator 5 to have a required beam shape and energy density, and an irradiation head 18 having an imaging lens for condensing the shaped laser beam. A work table 1 for moving the workpiece 50 in a plane perpendicular to the optical axis of the laser beam, and a base platen 3 on which the work table 1 is placed.

The laser beam is processed in the optical system 6 as shown in FIG. 3, for example, to be processed. Specifically, the laser beam emitted from the laser oscillator 5 passes through an acousto-optic device (AOM) 23 which is a switching device, is reflected by a reflection mirror 24, and is reflected by a phase difference plate 25 and a diffusion prevention lens 26. After being reflected by the mirror 27, the first beam splitter 28
Is split into linearly polarized light traveling in two directions. The two split beams emitted from the first beam splitter 28 are respectively reflected by reflecting mirrors 29 and 32,
After passing through the optical fibers 43 and 44, passing through the phase difference plates 30 and 33, and being expanded into the oval shape through the lenses 31 and 34, the respective beams are further expanded in two directions by the second beam splitters 35 and 35. The light is split into incoming linearly polarized light.

As a result, the laser beam is split into four beams that have been processed to have the desired beam shape and energy density. These split beams pass through an apertured mask 36 and a converging lens 37
After passing through the imaging lens 38 and / or the like, the beam is irradiated from the objective lens 39 toward the processing surface A so as to be focused in a spot shape, and as a result, the irradiated portion can be laser-processed. it can.

[0007]

As an example of a case where a transparent electrode of a plasma display apparatus is trimmed by using the above-described laser processing apparatus, first, as shown in FIG. A thin film 51 of ITO (indium-tin-oxide), which is a transparent electrode material, is provided on one side of a transparent substrate 50 made of a flat glass substrate or the like having a substantially rectangular planar shape by a method such as sputtering. Is adhered in a predetermined shape (for example, a square shape similar to the transparent substrate) on an inner portion except for an outer peripheral side portion of. Next, as shown in FIG.
X-axis direction (hereinafter, in the present invention, with reference to the drawings,
When the substrate is referred to as the XY axis direction, the horizontal direction in the drawing sheet is referred to as the X axis direction, and the vertical direction in the drawing sheet is referred to as the Y axis direction. ), The processing start positions are set at a predetermined pitch interval, and the laser beam applied to each processing start position is scanned in the Y-axis direction of the ITO thin film 51, and the ITO thin film existing at the irradiated portion is irradiated with the laser beam irradiation heat. To remove. As a result, a portion of the ITO thin film 51 having a predetermined short width in the X-axis direction of the transparent substrate 50 and having an elongated rectangular shape extending in the Y-axis direction of the transparent substrate 50 serves as a transparent electrode 52 on the transparent substrate 50. In addition, a plurality of adjacent straight lines are formed at a predetermined pitch interval in the X-axis direction. The transparent electrode 52 formed by such a patterning process is
As shown in FIG. 5B, a plurality of substantially parallel straight lines are distributed in an inner portion of the transparent substrate 50 except for an outer peripheral portion.

In such laser processing, in order to efficiently use the energy of the laser beam, the laser beam is formed by using a coupling optical system such as an imaging lens 38 formed by combining a plurality of lenses as shown in FIG. The state of the laser beam that is condensed, focuses on the focal point, and forms an image is schematically shown as a portion indicated by reference numeral S in FIG. In this case, the focal length W and the focal depth of the laser beam are determined by the combination of lenses used as the coupling optical system. Therefore, within the focal depth determined by the specific coupling optical system, the laser beam shape shaped by the aperture 65 can be accurately transferred, and an ideal patterning process can be performed.

[0009] Even when such precision processing is performed, a high throughput per unit time, and therefore a high processing speed, is required for industrial productivity. A combination of a laser oscillator and an optical system having a high imaging magnification is used.

In such a patterning process, when a high-output laser oscillator is used in combination with an optical system having a high imaging magnification, the divergence angle (divergence angle) of the laser is large, and the focal depth may be 20 μm or less. is there. However, a glass substrate is often used as the transparent substrate 50, and it is extremely difficult to obtain a glass substrate having a flatness of 20 μm or less on an industrial scale at a reasonable cost.

For example, in the case where the transparent electrode 52 is formed linearly in the patterning process as described above, a 20 μm
When a glass substrate having a flatness exceeding m is used as the transparent substrate 50, the flatness of the transparent substrate is 20 μm.
5 (c), a beam having a desired shape and energy intensity hits the ITO thin film 51 with respect to the portion within m, and the ITO thin film existing at the irradiation site exactly corresponds to the shape of the aperture 65, and FIG. Although it can be removed with an ideal rectangular cross section as schematically shown in Figure 2, the flat shape after removing the ITO thin film is used in the part where the flatness of the transparent substrate exceeds 20 μm. May not accurately correspond to the shape of the aperture 65, or the cross-sectional shape of the portion from which the ITO thin film is removed may not be an ideal quadrangle, and may have a curved wall surface in the cross-sectional shape. There is.

As a result, there is a problem that the contour accuracy of the transparent electrode 52 is reduced, and in some cases, a processing defect such as being unable to be used as a part for a transparent electrode of a plasma display device may be caused.

When the ITO thin film is trimmed, a part of the irradiation energy of the laser beam is transmitted to the transparent substrate 50 as heat energy, and the temperature of the transparent substrate 50 may increase during the processing. However, the pitch between the transparent electrodes of a plasma display panel (hereinafter, also referred to as PDP) is as small as 100 μm, or as small as 10 μm in some cases.

Therefore, in the above-described trimming process, when the laser beam scans on the transparent substrate 50 at such a small pitch feed, the transparent substrates 50 are spaced at intervals of about 100 μm in the X-axis direction, for example. And in the Y-axis direction, over almost the entire length, 50 MW
/ Cm ² , the transparent substrate 50 is heated as a whole and the temperature rises,
As a result, the transparent substrate 50 can expand.

In such a case, if the temperature distribution is substantially uniform in the glass substrate to be processed, the glass substrate expands at the same rate in the vertical and horizontal directions, and the glass substrate expands almost in the state before expansion. A similar shape can be maintained. However, the way of temperature rise may be uneven for the entire glass substrate. For example, when the temperature of the central portion rises more than the temperature of the peripheral portion, as shown in FIG. The rectangular glass substrate may have a shape in which each of its four sides is outwardly convex as shown in FIG. 6B by thermal expansion.

As described above, when the transparent electrode 52 is irradiated with a laser beam so as to draw a plurality of adjacent straight lines at a predetermined pitch interval in a state where the transparent substrate 50 is thermally expanded, trimming is completed. Later, the transparent substrate 5
When the temperature of 0 is lowered to room temperature, the transparent substrate 50 contracts, and as a result, the transparent electrodes 52, which are substantially parallel straight lines on the expanded transparent substrate 50, become parallel to each other. Will not be able to keep.

For example, when observing two outermost lines of a plurality of straight lines adjacent in parallel, when the substrate is expanded, the two lines are parallel to each other. The two straight lines located on the outside can be deformed into a shape like a concave lens whose center is narrowed. Although depending on the degree of deformation, the transparent substrate 50 whose degree of deformation exceeds an allowable range cannot be used as a part for a transparent electrode, and such a phenomenon also causes processing failure.

If the degree of expansion due to heat is not uniform over the entire substrate,
In a laser processing device, the work table and the irradiation head are moved at a relatively constant interval to determine the pitch interval, and the laser beam is irradiated to perform processing. In some cases, the pitch between the formed electrodes cannot be kept constant.

Accordingly, the present invention provides a method for performing precise laser processing such as trimming of a thin film at a high processing speed.
It is an object of the present invention to solve the above-mentioned problems and to provide an apparatus capable of efficiently performing laser processing with high accuracy.

Further, the present invention solves the above-mentioned problems in performing precise laser processing such as trimming of a thin film at a high processing speed, and can efficiently perform laser processing with high precision. Another aim is to provide a method that can be done.

[0021]

SUMMARY OF THE INVENTION In one aspect, the present invention provides an optical system having a laser oscillator, a mask for shaping a laser beam, an imaging lens for focusing the shaped laser beam, and a workpiece. A work table that moves the workpiece in a plane perpendicular to the optical axis of the laser beam, a displacement meter that measures the distance of the workpiece to the surface of the workpiece, Means for adjusting the focal length of the laser beam based on three-dimensional data measured in advance on the surface, and an imaging lens, so that the irradiation head for emitting the laser beam scans the workpiece over a predetermined path. And a means for driving a work table.

According to another aspect of the present invention, there is provided an optical system having a laser oscillator, a mask for shaping a laser beam, an imaging lens for focusing on the shaped laser beam, and a method for mounting a workpiece on the laser beam. A work table for moving the object in a plane perpendicular to the optical axis of the laser beam, and a laser processing apparatus having a displacement gauge for measuring a distance to a surface of a processing target in the processing target,
Provided is a laser processing apparatus, further comprising: means for measuring a temperature of a workpiece; and means for calculating a degree of expansion of the workpiece based on the measured temperature and adjusting a processing pitch. .

The present invention provides, in yet another aspect,
A laser oscillator, an optical system having a mask for shaping the laser beam, and an imaging lens for focusing the shaped laser beam, a work to be placed thereon, and the work to be processed in a plane perpendicular to the optical axis of the laser beam. A method of performing laser processing using a laser processing apparatus having a work table to be moved within a workpiece, and a displacement meter for measuring a distance to a surface of a workpiece in a workpiece. Adjusting the focal length of the laser beam based on three-dimensional data measured in advance on the surface of the processing portion, and a work table such that the irradiation head including the imaging lens moves on the processing portion along a predetermined scanning path. And a step of driving the same.

The present invention provides, in still another aspect,
A laser oscillator, an optical system having a mask for shaping the laser beam, and an imaging lens for focusing the shaped laser beam, a work to be placed thereon, and the work to be processed in a plane perpendicular to the optical axis of the laser beam. A method of performing laser processing using a laser processing apparatus having a work table to be moved within a workpiece, and a displacement meter for measuring a distance to a surface of a workpiece in a workpiece, and measuring a temperature of the workpiece. And adjusting a processing pitch by calculating a degree of expansion of the workpiece based on the measured temperature.

In the present invention, the three-dimensional data on the surface of the workpiece is defined by three-dimensional coordinates based on a work table or a specific location on the surface of the workpiece. It means data expressed as a value on a certain XYZ coordinate. In this type of processing, when the work is placed on the work table, the work is always mounted in a fixed positional relationship with the work table to maintain the processing accuracy. Even when a reference point of coordinates is set on the table, the XYZ coordinates of the surface of the processed portion can be grasped in the same manner as in the case where a specific point on the surface of the processed portion is used as a reference.

In the present invention, the three-dimensional data measured in advance on the surface of a portion to be processed (hereinafter also referred to as a substrate) means that a laser beam is applied from the irradiation head 18 to a workpiece placed on a work table. It means three-dimensional data of the surface of the workpiece measured at a point in time before the point where the workpiece is actually processed by irradiation. Therefore, before the point when the substrate is actually processed, whether immediately before processing the substrate, a predetermined time in seconds, minutes, or hours, or the substrate is placed on a work table. It is meant to include measurements at any of these times, whether after placement or before placement.

In the present invention, “scanning the irradiation head over the processing portion” means that the irradiation head moves over the processing portion along a predetermined path, and at the same time, the laser beam is applied to the processing object. The irradiation point to be irradiated moves so as to draw (trace) a predetermined graphic pattern on the processed portion.
In the present invention, such a trace of the irradiation point moving on the processing target portion is also referred to as a processing locus.

The predetermined path means a path along which the irradiation point scans a predetermined pattern on the workpiece to be formed on the surface of the workpiece by laser processing along a predetermined forward path. Therefore, in the XY plane, this path can be various patterns such as only a straight line, only a curve, or a combination of a straight line and a curve, depending on the type of the workpiece.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) First, a laser processing apparatus according to one aspect of the present invention will be described. The basic configuration of the laser processing apparatus according to the present invention is almost the same as that of a conventional laser processing apparatus as described in the section of the prior art. For example, as shown in FIG. An X-axis guide 11 and an X-axis drive unit 12 are provided, and an X-axis table 14 is mounted on the upper surface side of these.
A Y-axis guide 9 and a Y-axis drive unit 10 are provided on the upper surface side of the axis table 14, and the work table 1 is mounted on these upper surface sides. A transparent substrate 50 is placed on the upper surface side of the worktable 1, and a temperature sensor 16 for measuring the temperature near the transparent substrate 50 is embedded on the surface of the worktable 1.

On the upper surface of the surface plate 3, a gate-shaped column 2 is provided so as to straddle the work table 1. Four laser oscillators 5 are mounted on the upper surface side of the column 2, and each laser oscillator 5 is provided with an optical system 6, and an irradiation head 18 is provided at an exit portion of the optical system 6. I have. The laser beam emitted from the laser oscillator 5 is guided to the irradiation head 18, is condensed and shaped during that time, and is irradiated from the irradiation head 18. Irradiation head 18
Is a transparent substrate 5 placed horizontally on the work table 1.
The laser beam is irradiated perpendicularly to the upper surface of the laser beam. While passing through the optical system 6, the laser beam is processed in the same manner as described in the section of the prior art.

At the exit of the optical system 6, the laser beam 67 is adjusted to an appropriate beam diameter by a variable expander 60, as shown in FIG. . Subsequently, the laser beam 67 is divided into three laser beams each having necessary energy by the three-division prism 62. The laser beam split into three beams has an aperture 6
After being formed into a shape required for processing by the image forming device 5, the image is reduced and projected by the imaging lens 38, and is irradiated on a thin film 51 such as an ITO film formed on the surface of the transparent substrate 50.
Form 2

Therefore, in this example, the laser beam 67 emitted from one laser oscillator 5 is
The ITO thin film 51 disposed on the upper surface is irradiated with three divided beams on the processing surface. Further, in this example, since four laser oscillators 5 are provided in one laser processing apparatus, it is possible to simultaneously process 12 locations using a total of 12 laser beams. However, the number of laser oscillators used and the number of laser beams to be split can be set to various numerical values as desired.

At the exit of the optical system 6 including the irradiation head 18, means for adjusting the focal length of the laser beam is provided. This means comprises an aperture 65
And / or adjusting means for moving the imaging lens 38 in order to move the mask 36 having an optical axis in the optical axis direction of the laser beam.

The means for driving the mask varies the distance between the mask and the imaging lens by moving (elevating) the mask 36 in the optical axis direction of the laser beam, and thus adjusting the focal length of the laser beam. Can be. In the example shown in FIG. 2, the driving unit includes the motor 63 and the ball screw 6.
Although it is formed by the combination of the four, various means such as a linear motor, a rack and pinion, and the like can be adopted as long as the means can drive the object in one axial direction. However, as the driving means, the mask 36 may be fixed and the system of the imaging lens 38 may be moved in the direction of the optical axis of the laser beam. Alternatively, the mask 36 and the imaging lens may be used. It is also possible to adopt a configuration in which both of the 38 systems are moved.

Therefore, the focal length of the laser beam can be adjusted by driving the mask driving means or the imaging lens 3 as described above.
8 or by a combination of a mask driving means and an imaging lens 38 adjusting means. When processing, work table 1
Is moved in the XY plane, the height of the surface of the work table 1 at the irradiation point of the laser beam (the numerical value of the Z coordinate) changes due to the undulation of the surface of the workpiece, but the degree is measured in advance. The focal length of the laser beam can be adjusted by the above-described adjustment mechanism so as to correspond to the change in the height, since the data is grasped based on the data.

Next, the operation of feeding the transparent substrate 50 will be described with reference to FIG. On the upper surface side of the surface plate 3,
X-axis guides 11 and X extending in a direction along one side surface (in this example, this direction is referred to as an X-axis direction for convenience)
An axis drive unit 12 is provided, and an X-axis table 14 is provided on the upper surface side. The X-axis table 14
Since it is engaged with and attached to the axis guide 11, it can be moved only in the direction along the X-axis guide 11, and the X-axis drive unit 12 causes the X-axis table 14 to move in the X-axis direction. .

On the upper surface of the X-axis table 14, a Y-axis guide 9 and a Y-axis driving unit 10 are provided in a direction orthogonal to the X-axis guide 11, and the work table 1 is provided on the upper surface.
Are arranged. The work table 1 has a Y-axis guide 9
The work table 1 can be moved only in the direction along the Y-axis guide 9 and is moved by the Y-axis drive unit 10 in the Y-axis direction.

On the upper surface side of the work table 1, a transparent substrate 50 as a workpiece is placed. For example, the work table 1 is moved by the X-axis drive unit 12 and the Y-axis drive unit 10 while being controlled by control means such as a computer (not shown). X- on the surface of
It can be controlled to hit an arbitrary position on the Y plane. In this example, a linear motor is used as the X-axis drive unit 12 and the Y-axis drive unit 10, but other objects such as a rack-and-pinion or a combination of a rotary motor and a ball screw may be used in one axial direction. Can be adopted.

When the transparent electrode of the plasma display panel is trimmed by using such a laser processing apparatus, as described above, the ITO thin film 51 is provided on one side as shown in FIG. The deposited transparent substrate 50 is placed at a predetermined position on the work table 1, and the work table 1 is driven in the Y-axis direction while irradiating a laser beam from the irradiation head 18. If the relative movement in this case is observed from the transparent substrate 50 side, the irradiation head 18
Scans the transparent substrate 50 in the Y-axis direction. In the case of this example, the scanning path along which the irradiation head moves over the workpiece is a path (pattern) in which a plurality of straight lines are adjacent in parallel as shown in FIG.
At the same time, twelve laser beams impinge on the ITO thin film 51 to form eleven or twelve parallel transparent electrodes 52 adjacent to each other at a predetermined pitch.

In the example shown in FIG. 1, the displacement gauge 15 is disposed on the side of the irradiation head 18. A displacement meter is a device that measures the distance between a displacement meter and an object (substrate) at a remote position. For example, a laser, an electromagnetic wave (including sound waves and ultrasonic waves), and / or light (visible light) And the like (including infrared rays) can be used alone or in combination. In this example, a displacement meter using a laser is used. In one embodiment, the displacement gauge 15 is aimed at an irradiation point on the substrate 50, which is a portion to which the laser beam emitted from the irradiation head 18 strikes. It is provided so that the distance between them can be calculated.

The position where the displacement gauge 15 is disposed is not limited to the side surface of the irradiation head, but may be any other position as long as the relative positional relationship between the displacement gauge and the workpiece on the work table can be grasped. be able to. This is the displacement meter and irradiation head 1
8 and the angle between the straight line connecting the displacement meter 15 and the irradiation head 18 to the straight line connecting the displacement meter 15 and the workpiece, the displacement meter 15 and the workpiece are Is calculated as described above, the actual distance between the irradiation head 18 and the workpiece (see FIG. 2) based on the triangulation principle that a specific triangle is determined by two sides and its included angle. L) shown in FIG.

As the data measured in advance, (a) when there is no path already scanned by the irradiation head at a position adjacent to the path to be scanned, the irradiation head scans as three-dimensional data measured in advance. The data obtained by measuring the distance to the surface of the portion to be processed by the displacement meter for the immediately preceding path can be used, or (b) the path already scanned by the irradiation head is located at a position adjacent to the path to be scanned. In some cases, as the pre-measured three-dimensional data, when the irradiation head has passed an adjacent path that has already been scanned, data obtained by measuring the distance from the surface of the portion to be processed by the displacement meter on the path is used. be able to.

In the present invention, the term “adjacent” means
It means that they are relatively close to each other. In particular, an adjacent point for a specific point on the path to be scanned is a point having an XY coordinate value relatively close to the XY coordinate value of the specific point, Further, although there is a difference in the height (value of the Z coordinate), the difference in the height is very small, meaning a point that has a substantially negligible relationship. Therefore, in the present invention, the adjacent positional relationship is
In particular, it cannot be defined by numerical values, and when the above relationship is established depending on the type of the workpiece,
It can be called an adjacent position.

Therefore, the path that has been scanned by the irradiation head, which is located adjacent to the specific scanning path, is the position where a part of a certain continuous length is adjacent to the predetermined path that scans the workpiece. When there is a relationship, it means that part, but even when a part of the predetermined path does not have an adjacent positional relationship over a certain length, the above-described close path from the already scanned paths By extracting points having the values of the XY coordinates and considering a set of those points, it is possible to consider an already scanned path in an adjacent positional relationship.

(A) If there is no path already scanned by the irradiation head at a position adjacent to the path to be scanned, the three-dimensional data measured in advance is used to displace the path immediately before the irradiation head scans. In the aspect using data obtained by measuring the distance to the surface of the workpiece by the meter,
In the scanning path, by providing a displacement meter with aiming ahead of the irradiation point of the laser beam, it is possible to scan immediately before the irradiation head scans in the path to be scanned as three-dimensional data measured in advance. Then, the distance to the substrate surface on the path is measured, and the focal length of the laser beam is adjusted using the obtained data.

If there is a path already scanned by the irradiation head at the position (b) adjacent to the path to be scanned, the adjacent path already scanned by the irradiation head is used as three-dimensional data measured in advance. In a mode in which data obtained by measuring the distance to the surface of the workpiece with the displacement meter is used for the path when passing, the path that has already been scanned is a continuous length having a path that has scanned the workpiece. Are located in an adjacent positional relationship, the three-dimensional data based on the distance from the surface of the workpiece to be measured when the part is scanned by the displacement meter is used as the three-dimensional data measured in advance.

If there is a path already scanned by the irradiation head at the position (b) adjacent to the path to be scanned, the irradiation head already scans the adjacent path as three-dimensional data measured in advance. In a mode in which data obtained by measuring the distance from the surface of the workpiece with the displacement meter when passing through the path is used, the path that has already been scanned is closer to the path to be scanned by XY.
In the case of a set of points having coordinate values, the values of the XY coordinates of each point on the scanned path are represented by one graphic or XY coordinate along the path to be scanned. By reflecting the value of the Z coordinate for each point in this figure or graph,
Dimensional data can be formed.

Therefore, when there is no pre-measured three-dimensional data that can be used, at a position on the path immediately before scanning, as in a so-called auto focus,
Scanning is performed while measuring data relating to the distance. If pre-measured three-dimensional data already exists for an available adjacent position, the three-dimensional data is regarded as having substantially the same value. Then, it applies to the path to be scanned.

(B) The three-dimensional data measured in advance can be obtained by measuring the distance from the surface of the portion to be processed by the displacement meter when the irradiation head has passed an adjacent path that has already been scanned. In the mode using data, while the irradiation head scans on a predetermined path, the displacement meter measures the distance to the substrate surface, but the data obtained by the measurement is not used for processing on the path, It can be used when processing a route adjacent to the measured route.

This concept is based on the assumption that the X-coordinate and / or the Y-coordinate within a certain range of the surface of the workpiece is
This can be applied to the case where the value of the Z coordinate changes slowly. For example, when a flat glass plate is used as a workpiece, the surface of the flat glass is hardly completely flat when observed in a unit of μm, and gently undulates in the X-axis direction and the Y-axis direction. Can be expressed as In the present invention, gently undulating means that the surface is
At positions close to each other in the horizontal direction, the height changes, but the difference in height is very small, meaning that it is substantially negligible. For example, when a section having a length of 1 mm in the X-axis direction is arbitrarily selected on the surface of the processed portion, in the section, the surface of the processed portion has 0 or 1 convex portion, and the concave portion has Also, there is zero or one portion, and the displacement of the surface of the processed portion in the Z-axis direction is a surface state that can be considered to be about several μm. Here, the displacement means a shift amount as a deviation or a length from a reference plane defined for the surface of the processed portion at each point.

More specifically, the scanning path along which the irradiation head moves over the portion to be processed is shown in FIG.
In the case of processing a path of a first straight line portion in the case of a path (pattern) in which a plurality of straight lines are adjacent to each other in parallel as shown in FIG. Since there is no data, (a) as the pre-measured three-dimensional data, the data obtained by measuring the distance to the surface of the workpiece using the displacement meter for the path immediately before scanning by the irradiation head is used. Scanning is performed while measuring data on the distance at the position immediately before the scanning. When processing the path of the n-th (n ≧ 2) linear portion, (b) three-dimensional data measured in advance:
When the irradiation head has passed an adjacent path that has already been scanned, the irradiation head uses the data obtained by measuring the distance to the surface of the portion to be processed by the displacement meter for the path, so that the irradiation head uses the (n-1) th linear portion. When scanning the path of
The data of the distance measured by the displacement meter with respect to the path of the (n-1) -th linear part is applied to the path of the n-th linear part.

(A) As three-dimensional data measured in advance,
In the mode using the data obtained by measuring the distance to the surface of the workpiece using the displacement meter for the path immediately before the irradiation head scans, the measured data is applied to the processing while the measurement is being performed. Then, the distance is calculated, and the obtained data is sent to the adjustment means for aiming of the laser beam, and the processing is performed while applying the data.As a time required for the processing, the actual time of these steps is required,
There is a problem that the processing speed is limited and high-speed processing cannot be performed. However, in the present invention, (a) data obtained by measuring the distance from the surface of the processed portion using the displacement meter on the path immediately before scanning by the irradiation head is used as the three-dimensional data measured in advance. Rather than being used for processing the entire surface of the processed part, it is used for a part of the processed part, and for the remaining part of the processed part, there is an already scanned path having an adjacent positional relationship, so that (b) As the pre-measured three-dimensional data, an embodiment is used in which, when the irradiation head has passed an adjacent path that has already been scanned, data obtained by measuring the distance from the surface of the portion to be processed by the displacement meter is used for the path. be able to.

(B) As three-dimensional data measured in advance,
According to the aspect in which the data obtained by measuring the distance to the surface of the workpiece by the displacement meter is used for the path when the irradiation head has passed an adjacent path that has already been scanned, the measurement, calculation, and data feeding steps are performed. Since it is not necessary to perform the processing in real time, and it is possible to perform processing using existing data, the time required for processing by the laser beam itself is shorter than the time required for the laser beam to scan on the surface of the workpiece. The time required can be made substantially equal. Therefore, the same path is measured by measuring the distance from the surface of the portion to be processed by the displacement meter on the path immediately before scanning by the irradiation head as (a) three-dimensional data measured in advance. The time required for processing can be significantly reduced as compared with the case where processing is performed using the obtained data.

Therefore, in the present invention, (a)
As the pre-measured three-dimensional data, a mode in which data obtained by measuring the distance to the surface of the workpiece using the displacement meter for the path immediately before scanning by the irradiation head is used, and (b) the pre-measured three-dimensional data is When the irradiation head has passed an adjacent path that has already been scanned, laser processing is performed in combination with a mode that uses data obtained by measuring the distance to the surface of the workpiece using a displacement meter for that path. Can be performed at high speed, and the time required for processing the workpiece can be greatly reduced.

In particular, (a) an embodiment in which, as the pre-measured three-dimensional data, a mode in which data obtained by measuring the distance from the surface of the portion to be processed by the displacement meter on the path immediately before scanning by the irradiation head is applied. , (B) 3 previously measured
As the dimensional data, when the irradiation head has passed an adjacent path that has already been scanned, the path using the data obtained by measuring the distance from the surface of the processed part using the displacement meter with respect to the path is relative to the part to which the mode is applied. If the scanning path is set so as to be smaller in size, processing at a higher speed can be performed.

Therefore, when the scanning path is a plurality of straight lines adjacent in parallel, only the first path (a)
As the pre-measured three-dimensional data, a mode is used in which data obtained by measuring the distance from the surface of the portion to be processed by the displacement meter with respect to the path immediately before scanning by the irradiation head is applied.
For the subsequent paths, (b) as the pre-measured three-dimensional data, when the irradiation head has passed an adjacent path that has already been scanned, the distance from the path to the surface of the portion to be processed is measured using a displacement meter. Since the mode using the obtained data can be applied, the effect of shortening the processing time according to the present invention is increased.

(Embodiment 2) In another embodiment of the present invention, when a radiation head scans a workpiece of a specific kind on a workpiece with a plurality of predetermined three-dimensional data as pre-measured three-dimensional data. Based on the distance data obtained by measuring the displacement meter for the point, the value of the XY coordinate at each point on the surface of the workpiece, and the displacement from the reference plane defined for the surface of the workpiece at each point. Data obtained by associating the values with certain Z coordinates can be used.

That is, as three-dimensional data measured in advance,
For a specific type of workpiece of the same type as the workpiece to be machined, values of XY coordinates, which are coordinates in a horizontal plane at each point on the surface of the workpiece, and the surface of the workpiece at each point are determined in advance. Measures the value of the Z coordinate, which is the displacement from the reference plane, and analyzes the obtained measured value, and when it can be grasped as a specific pattern, associates the displacement between the XY coordinate and the Z coordinate. Use the data compiled as data.

In this embodiment, when a flat glass plate or the like is used as a workpiece, a displacement (ΔZ) from a reference plane in a horizontal plane of a certain width (a section of XY coordinates in a certain range). Measures three-dimensional data on a plurality of workpiece surfaces for each type of workpiece based on what can be considered to fluctuate in a specific pattern, and stores the data as data that can refer to the characteristic pattern. I do. In this case, by picking up a plurality of points having a specific positional relationship on the XY coordinates, data in a form in which three-dimensional data applicable to the surface of the specific type of workpiece can be extracted. It is preferable that If the three-dimensional data of the surface is created in accordance with the type of the workpiece in this manner, when the same specific type of workpiece is subsequently processed, the already created three-dimensional data is referred to. Can be.

Therefore, even if the three-dimensional data is not measured for the entire workpiece to be machined, if the measurement is performed at several necessary points, the data obtained at the several points is stored. 3D data that can be applied to the entire workpiece
You can know dimensional data. Such a measurement is referred to as a simple measurement in the present invention.

Such a mode is a means for accumulating three-dimensional data measured in advance for a specific type of workpiece, a means for simply measuring three-dimensional data on a processed portion of the workpiece to be processed, And a means for comparing the simply measured three-dimensional data with the stored three-dimensional data to determine three-dimensional data to be applied to the workpiece to be processed. It is preferable to use a laser processing device that can move the irradiation head based on the laser processing. This simple measurement can be performed during or before the processing. In a mode in which the simple measurement is performed at the time of the processing, the means for simply measuring the image forming lens and the surface of the portion to be processed by the displacement meter while the irradiation head scans the scanning path during the processing. A means for measuring the distance can be used.

Here, the measurement during the scanning of the scanning path means that the measurement is performed after the processing of a specific workpiece is started and before the processing of the workpiece is completed. Means. However, since this aspect aims at obtaining the three-dimensional data to be applied to the workpiece in the shortest possible time in order to improve the processing efficiency, after starting the processing on the specific workpiece, In the above, it is preferable to perform the measurement in as short a time as possible. In order to perform the measurement in a short time, the measurement may be performed at a minimum point required for obtaining information for obtaining three-dimensional data on the entire workpiece.

For a specific type of workpiece, three-dimensional data measured in advance is stored in a form that can be referred to, and information for grasping the three-dimensional data of the workpiece is stored on the workpiece, for example. , XY coordinates, (X ₀ ,
Y ₀ ), (X _a1 , Y _b1 ) and (X _a2 ,
If three points of Y _b2 ) can be grasped, three-dimensional data applicable to the workpiece can be obtained in a very short time. Here, X _a1 and X _a2 are:
X-axis coordinates separated from X ₀ by a sufficient interval to know information necessary for specifying three-dimensional data, and Y _b1
And Y _b2 are similarly Y-axis coordinates separated from Y ₀ by a sufficient interval to know information necessary for specifying three-dimensional data. By connecting these three points, it is possible to obtain the minimum necessary triangle for grasping the pattern of the three-dimensional data on the surface of the processed portion.

In the aspect in which the simple measurement is performed before the processing, the simple measuring means measures the distance between the imaging lens and the surface of the portion to be processed by the displacement meter before the processing. Means can be used. In this case, before performing the processing on the specific type of workpiece, it is possible to perform a simple measurement in a unit of time, minute, second, or a unit of time shorter than a second before a fixed time. it can. Of course,
This aspect aims at obtaining the three-dimensional data to be applied to the workpiece in the shortest possible time in order to improve the processing efficiency. Therefore, immediately before starting the processing on the specific type of workpiece, Preferably, a measurement is made.

(Embodiment 3) The laser processing apparatus of the present invention is applicable to any of the above-described Embodiments 1 and 2 or other forms. The apparatus may further include means for measuring the temperature of the object, and means for calculating the degree of expansion of the workpiece based on the measured temperature and adjusting the processing pitch. This is because, when processing with a laser beam, the temperature of the workpiece increases due to the irradiation energy of the laser beam, and the workpiece can thermally expand and deform, so that the temperature of a specific type of workpiece increases. Data on the degree and the degree of deformation due to thermal expansion at the increased temperature is collected in advance and stored as data in a form that can be referred to, and if the temperature of the workpiece is measured during processing, the Based on the idea that the degree of deformation of the workpiece can be grasped.

As means for measuring the temperature of the workpiece,
In the example shown in FIG. 1, a temperature sensor 16 embedded in the surface of the work table 1 is used. For example, in the case described above as an example, the workpiece thermally expands,
For example, in the case of a non-uniform temperature distribution in which the degree of temperature rise in the central part is greater than that in the peripheral part, the workpiece has four peripheral sides projecting outward as shown in FIG. Can be obtained.

For such a case, in the laser processing apparatus, means for accumulating data obtained by previously examining a deformation pattern which is thermally deformed at the time of processing a specific type of workpiece, and processing the workpiece in accordance with the deformation pattern. It can also be set up to have means for correcting the scanning path of the irradiation head on the part.

For example, a predetermined XY on a workpiece
(X _a1 , Y _b1 ) having coordinate values, (X _am ,
(X _a1 , Y _b1 ), by measuring the temperature at the point of Y _bm ) and based on the information, the degree of deformation of the workpiece at that time and the shape of the entire workpiece can be grasped.・ ・
It is preferable to set each point of the coordinates of (X _am , Y _bm ) and to collect in advance data on the temperature and the degree of deformation due to thermal expansion at that temperature.

Here, the position of the measuring point as a whole of the workpiece, the number of the measuring points, the interval between the measuring points, and the pattern for distributing the measuring points on the workpiece are described. This is an element that can be appropriately set experimentally or empirically by a person skilled in the art for a specific type of workpiece to be used. Therefore, the present invention discloses the above-described basic idea, but a person skilled in the art can appropriately select a specific method of measuring a specific type of workpiece based on the disclosure content of the present specification. And can be determined.

As described above, in the case where each of the four sides around the workpiece has an outwardly convex shape, a plurality of straight lines whose scanning paths are substantially parallel and adjacent to each other on the workpiece are defined. In the case of a pattern to be drawn, if the processing is performed by setting a scanning path on a curved curve as shown in FIG. 6 (b), when the temperature of the workpiece falls to room temperature, the whole A processing pattern in which a plurality of straight lines are adjacent to each other in parallel can be formed on a rectangular processing target portion.

As described above, the work table 1 on which the workpiece 50 is mounted is driven in the Y-axis direction while irradiating the laser beam from the irradiation head 18 as described above. In synchronization with the operation of Step 1, the irradiation point of the laser beam
The operation is performed by relatively driving the work table 1 and the irradiation head 18 so as to scan on a curved curve as shown in (b), so that the machining trajectory draws such a curve. it can.

When the workpiece moves in the Y-axis direction due to the movement of the work table 1, if the exit portion of the optical system is moved in the X-axis direction in conjunction with the amount of the movement, the scanning path is curved as described above. You can draw a curved line. At the exit of the optical system, as shown in FIG. 2, the laser beam generally has a smaller beam diameter after exiting the imaging lens 38 than before entering the imaging lens 38. In the example of the present invention, the beam diameter is reduced to about 1/5.

Therefore, the image forming lens 3
The scanning path can be drawn with higher accuracy by adjusting the position by the mask 36 than by adjusting the position by the mask 8. This is because, for example, in order to ensure the accuracy of 2 μm on the workpiece, if the alignment is to be performed by the objective lens 39, the 2 μm must be adjusted by the imaging lens 38. In order to adjust the alignment by using a mask, it is only necessary to obtain an accuracy of 10 μm obtained by multiplying this 2 μm by the magnification of the image forming ratio. It is.

(Embodiment 4) Further, the laser processing apparatus of the present invention can be used in any of the above-described Embodiments 1 to 3 or other forms. Before applying the method, a reference mark indicating a processing start position by a laser beam can be formed on the surface of the processed portion of the processed material that is not expanded at room temperature.

The fiducial mark is one type of mark formed at the processing start position of the processed portion for irradiating a laser beam. In order to reduce the processing time and the operation cost, the reference mark is preferably provided so that it can be erased by a laser beam applied to the reference mark. If this is not the case, it is necessary to provide another step for erasing the fiducial mark. However, if time and / or operation costs do not need to be particularly emphasized, another step may be provided and other means may be used. The reference mark can be deleted. However, the reference mark may not always need to be erased.

When the reference mark is erased by the laser beam to be irradiated, for example, the laser beam is spot-shaped at a predetermined pitch interval with respect to the surface of the portion to be processed which is not expanded at room temperature. And the reference mark can be used after the irradiation.
When the workpiece is a glass substrate, in a state where the workpiece is not expanded at room temperature, the transparent electrode serving as the surface of the workpiece is irradiated with a laser beam in a spot shape at a desired predetermined pitch interval in the X-axis direction. Then, the irradiation trace can be used as a reference mark.

In this case, the conditions of the laser beam used for forming the reference mark, for example, factors such as the output and the beam diameter may be the same as those of the beam for performing the ordinary laser processing. It is just a mark to indicate the processing start position and again at the same position,
When irradiating a beam for processing, the output is weaker than the laser beam irradiating at the time of laser processing, considering that only the part with the reference mark will be excessively irradiated with the laser beam. And / or a smaller beam diameter.

At the time of processing, a reference mark is detected by a detector provided on the side surface of the irradiation head in the laser processing apparatus, and the processing start point can be determined. The detector only needs to have a mechanism capable of detecting the position of the reference mark corresponding to the reference mark to be formed.
For example, when the reference mark is formed in a form that can be optically observed, as the detector, a combination of optical lens systems, for example, a microscope can be used,
When the reference mark is formed by magnetic means, a detector having a mechanism capable of detecting magnetism can be used as the detector. Even in other cases, the detector is not processed. A mechanism corresponding to the form of the reference mark that can detect the reference mark attached to the surface of the unit is used.

The position where the detector is provided may be, for example, on the side surface of the irradiation head in the laser processing apparatus, but is not limited thereto. If the relative positional relationship with the workpiece on the table can be grasped, it can be provided at another position of the laser processing apparatus. During processing, if the workpiece thermally expands, the distance between the reference marks will also increase, but if the temperature returns to room temperature and then contracts, the distance between the reference marks will return to the initially set predetermined pitch interval. By irradiating the laser beam with the reference mark on the surface of the portion to be processed deformed by expansion as a processing start point, it is possible to form a scanning path of the laser beam at a correct pitch interval as desired after laser processing. it can.

Therefore, even when the workpiece is deformed non-uniformly as a whole due to thermal expansion during the laser machining process, the irradiation point of the laser beam can be accurately positioned on the surface of the workpiece. Thus, a processing locus of a desired pattern can be formed with high accuracy on the surface of the processed portion that has returned to room temperature. In the present invention, the irradiation point of the laser beam does not necessarily have to be continuous on the scanning path, in any of the embodiments or aspects, for example, the laser beam is irradiated on a predetermined path. Processing can also be performed by irradiating in the form of spots at intervals.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of a laser processing apparatus according to one embodiment of the present invention.

FIG. 2 is a sectional view schematically showing an exit portion of an optical system of the laser processing apparatus.

FIG. 3 is a schematic diagram showing a processing path of a laser beam in a laser processing apparatus.

FIG. 4 is a schematic diagram illustrating a state of a laser beam applied to a workpiece during laser processing.

FIG. 5 is a schematic diagram for explaining a process in a case where a transparent electrode is trimmed.

FIG. 6 is a schematic diagram showing a case where the expansion of a workpiece is non-uniform.

[Explanation of symbols]

Reference Signs List 1 work table, 2 column, 3 base plate, 5 laser oscillator, 6 optical system, 7 detector, 9 Y-axis guide, 10 Y-axis drive unit, 11
X-axis guide, 12 X-axis drive unit, 14 X-axis table, 15 Displacement gauge, 16 Temperature sensor, 18 Irradiation head, 23 Acousto-optical element, 24 Reflection mirror,
25 phase difference plate, 26 diffusion prevention lens, 27 reflection mirror, 28 beam splitter, 29 reflection mirror, 30 phase difference plate, 31 lens, 32 reflection mirror, 33 phase difference plate, 34 lens, 35 beam splitter, 36 mask, 37 Convergent lens,
38 imaging lens, 39 objective lens, 43/44
Optical fiber, 50 Workpiece (substrate), 51 ITO
Thin film, 52 transparent electrode, 60 variable exbander,
61 mask, 62 3-split prism, 63 motor, 64 ball screw, 65 aperture, 67
Laser beam, W focal length.

Continued on the front page (72) Inventor Hideki Tsutsumi 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 4E068 AC01 CA11 CA14 CB04 CB06 CC02 CC03 CC06 CD10 DA11 DB13

Claims (22)

[Claims] An optical system having a laser oscillator, a mask for shaping a laser beam, and an imaging lens for focusing on the shaped laser beam, a workpiece to be placed, and the workpiece to be placed on the optical axis of the laser beam. A work table that moves in a plane perpendicular to the surface, a displacement gauge that measures the distance of the workpiece to the surface of the workpiece, and the focal length of the laser beam is adjusted based on three-dimensional data measured in advance on the surface of the workpiece. And a means for driving at least one of the irradiation head and the work table by causing an irradiation head that emits a laser beam to scan a portion to be processed over a predetermined path. 2. The laser processing apparatus according to claim 1, wherein the focal length of the laser beam is adjusted by moving at least one of a mask and an imaging lens of the optical system. 3. The laser processing apparatus according to claim 1, wherein the irradiation head moves on a portion to be processed along a scanning path that draws a plurality of straight lines that are substantially parallel and adjacent to each other. 4. A means for accumulating three-dimensional data measured in advance for a specific type of workpiece, a means for simply measuring three-dimensional data on a processed portion of a workpiece to be processed, and Means for comparing the measured three-dimensional data with the stored three-dimensional data to determine three-dimensional data to be applied to the workpiece to be machined; and an irradiation head based on the determined three-dimensional data. The laser processing apparatus according to any one of claims 1 to 3, wherein the laser beam is moved. 5. A means for simply measuring is a means for measuring a distance between an imaging lens and a surface of a portion to be processed by a displacement meter while an irradiation head scans a scanning path during a processing process. The laser processing apparatus according to claim 4, wherein: 6. The laser processing apparatus according to claim 4, wherein the means for simply measuring is a means for measuring the distance between the imaging lens and the surface of the portion to be processed by a displacement meter. 7. A means for measuring the temperature of the workpiece, and calculating a degree of expansion of the workpiece based on the measured temperature,
The laser processing apparatus according to claim 1, further comprising a unit for adjusting a processing pitch. 8. An optical system having a laser oscillator, a mask for shaping a laser beam, and an imaging lens for focusing on the shaped laser beam, a workpiece to be mounted, and the workpiece to the optical axis of the laser beam. What is claimed is: 1. A laser processing apparatus comprising: a work table that moves in a plane perpendicular to a surface thereof; and a displacement meter that measures a distance to a surface of a workpiece in the workpiece, wherein the temperature of the workpiece is measured. And a means for calculating a degree of expansion of the workpiece based on the measured temperature and adjusting a processing pitch. 9. A processing apparatus comprising: a detector for detecting a fiducial mark provided on a portion to be processed of a workpiece, wherein the fiducial mark is detected by the detector to determine a processing start point. The laser processing apparatus according to any one of claims 1 to 8, wherein 10. A means for accumulating data obtained by previously examining a deformation pattern of a specific type of workpiece which is thermally deformed during processing, and correcting a scanning path of an irradiation head on a workpiece according to the deformation pattern. The laser processing apparatus according to claim 1, further comprising a unit. 11. A method for irradiating a laser beam from an optical system onto a surface of a workpiece, wherein the laser processing is performed based on three-dimensional data measured in advance on the surface of the workpiece. A step of adjusting a focal length, and a step of moving at least one of an irradiation head and a work table by moving an irradiation head including an imaging lens on a processing portion along a predetermined scanning path. how to. 12. (a) If there is no path already scanned by the irradiation head at a position adjacent to the path to be scanned, displacement as to the path immediately before the irradiation head scans as three-dimensional data measured in advance. Using data obtained by measuring the distance to the surface of the workpiece by means of a meter, and (b) measuring beforehand if there is a path that has been scanned by the irradiation head at a position adjacent to the path to be scanned. The data obtained by measuring the distance from the surface of the processing portion with the displacement meter when the irradiation head has passed an adjacent path that has been scanned by the irradiation head is used as the obtained three-dimensional data. 12. The method according to 11. 13. The three-dimensional data measured in advance based on distance data obtained by measuring a displacement meter at a predetermined point when an irradiation head scans a workpiece of a specific kind on a workpiece. The use of data obtained by associating the values of the XY coordinates at each point on the surface of the workpiece with the values of the Z coordinate, which is the displacement from the reference plane defined for the surface of the workpiece at each point, is used. A method according to claim 11 or claim 12, characterized in that: 14. The method according to claim 11, wherein the irradiation head moves along a scanning path that draws a plurality of straight lines adjacent to each other in a substantially parallel manner on the workpiece. 15. When the irradiation head scans on the first path, the distance between the imaging lens and the surface of the portion to be processed is measured by a displacement meter in a portion immediately before the irradiation head on the scanning path. In the case where the irradiation head scans on the n-th (n ≧ 2) and subsequent paths, the imaging lens and the workpiece are processed based on data measured by the displacement meter when scanning on the (n−1) -th path. 15. The method according to claim 14, further comprising: deciding a distance to the portion, and moving the irradiation head over the portion to be processed while adjusting a distance between the imaging lens and the surface of the portion to be processed within a predetermined range.
The described method. 16. A step of accumulating three-dimensional data measured in advance for a specific type of workpiece, a step of simply measuring three-dimensional data of a processed part of the workpiece to be processed, and Comparing the measured three-dimensional data with the stored three-dimensional data to determine three-dimensional data to be applied to a workpiece to be processed; and irradiating the head based on the determined three-dimensional data. The method according to any one of claims 11 to 15, wherein is moved. 17. A simple measurement is performed by measuring the distance between the imaging lens and the surface of the portion to be processed by the displacement meter while the irradiation head scans the scanning path during the processing. 17. The method according to claim 16, wherein 18. The method according to claim 16, wherein a simple measurement is performed by measuring a distance between the imaging lens and the surface of the portion to be processed by a displacement meter before performing the processing. 19. The method according to claim 19, further comprising the steps of: measuring a temperature of the workpiece; calculating a degree of expansion of the workpiece based on the measured temperature; and adjusting a processing pitch. Item 19. The method according to any one of Items 11 to 18. 20. A method for performing laser processing by irradiating a laser beam from an optical system to a surface of a workpiece, wherein the step of measuring the temperature of the workpiece and the expansion of the workpiece based on the measured temperature are performed. Calculating a degree and adjusting a processing pitch. 21. The method according to claim 11, further comprising a step of detecting a reference mark attached to a portion to be processed of the workpiece by a detector to determine a processing start point. The laser processing method as described. 22. A step of accumulating data obtained by previously examining a deformation pattern of a specific kind of workpiece which is thermally deformed during processing, and correcting a scanning path of an irradiation head on a workpiece according to the deformation pattern. The laser processing method according to any one of claims 11 to 21, further comprising a step.