KR20090039646A - Laser processing device and laser processing method - Google Patents

Abstract

A laser processing apparatus and method are provided to be used regardless of the malfunction of the micro mirror by securing the predetermined irradiation region. The laser processing apparatus comprises the spatial modulation element(4), the projection optical system, the irradiated area control means(26), the operation failed device detection means and control means(14). The spatial modulation device comprises a plurality of micro movable elements. A plurality of micro movable elements irradiates the laser beam to the object to be processed. The irradiated area control means controls the operation of the spatial modulation device according to the set up the irradiated area in advance. The operation failed device detection means detects the fault micro movable element.

Description

LASER PROCESSING DEVICE AND LASER PROCESSING METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus using a spatial modulation element such as a micro mirror array typified by a digital micro mirror device. In particular, in the process of manufacturing a substrate such as a liquid crystal display device, a defect region on the substrate is imaged. The present invention relates to a laser repair device which extracts by means of a laser beam and corrects it in accordance with the shape of the defect area.

Background Art Conventionally, in a laser processing apparatus, a device is known in which a laser beam irradiated to a workpiece is switched by a plurality of micromirrors so that processing is performed by varying the range and pattern to which the laser beam is irradiated.

In such a laser processing apparatus, since a high-power laser beam is irradiated to the micromirror surface which has a micro area, when a micromirror tends to deteriorate over time and once a micromirror deteriorates, for example, the mirror surface of a micromirror Inclination of the laser beam causes a problem that the irradiation position of the laser beam is shifted, resulting in a machining failure in the machining area, or a destruction of an area in which machining is unnecessary or an area where machining is finished.

In order to solve this problem, when a digital micromirror device (hereinafter referred to as DMD), which is one of the micromirror arrays composed of a plurality of micromirrors, is deteriorated, The exposure apparatus which moved the laser beam irradiation area | region on DMD which is not deteriorated by moving the installed mask is disclosed (for example, refer patent document 1). As an example of the means for measuring the deterioration state, the deterioration state is estimated by a laser beam emission time accumulation counter, the optical power is measured at a position corresponding to the imaging medium, and the deterioration state is detected from the lowering of the optical power. It is disclosed that the scattered light is measured by a photodetector provided for each drawing region, and the deterioration state is detected in accordance with the change of the increase.

In addition, by employing a DMD larger than the range used for laser beam irradiation, the deterioration element of the micromirror is detected by imaging the laser beam deflected in a direction away from the workpiece among the reflected light of the micromirror, and the detected deterioration element is not used. It is disclosed to change the irradiation area so as to avoid the deterioration element by sliding the whole DMD so as to improve processing reliability (see Patent Document 2, for example).

[Patent Document 1] Japanese Unexamined Patent Publication No. 2004-191660 (4 th to 8 th, FIGS. 7, 10 and 13)

[Patent Document 2] Japanese Patent Laid-Open No. 2006-227198

However, in the laser processing apparatus using the conventional micro mirror array as described above, if the deterioration element increases and a deterioration element is generated over the entire surface of the DMD, the deterioration element cannot be avoided even if the micro mirror array is slid. In this case, the machining may not be possible, and at that point, the laser processing apparatus is stopped and the laser processing apparatus cannot be used until the next time the micromirror array is replaced. When using a laser processing apparatus in the inside, there was a problem that the production line had to be stopped.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and even when the workpiece is prevented from being processed while avoiding the micro-mirror that has become poor in operation, a predetermined irradiation area can be secured and used continuously. It is an object to provide a laser processing apparatus and a laser processing method.

In order to solve the problems as described above, the present invention adopts the following configuration. That is, according to one aspect of the present invention, the laser processing apparatus of the present invention comprises: a spatial modulation element in which a plurality of micro movable elements are arranged so as to irradiate a workpiece with a desired shape in a laser beam emitted from a laser light source; A projection optical system arranged so that the spatial modulation element and the workpiece are in a conjugate position, irradiation area control means for controlling the operation of the spatial modulation element in accordance with a preset irradiation area of the irradiation, and the space modulation element The operation | movement when the position of the micro-movement element detection means which detects the micro-movement element which is a malfunction | operation among the micro-movement elements, and the position of the micro-movement element detected as operation failure by the said operation | movement element detection means overlap with the said irradiation area, The work piece is divided into a plurality of times by using a region where no defect is detected. Characterized in that a control means for controlling to perform four.

According to the present invention, when the position of the micromirror detected as defective in operation overlaps with the irradiation area, irradiation is performed by dividing the workpiece into a plurality of times using a normal area including only the micromirror not detected as defective in operation. Since it can be performed, even when it becomes a state which cannot process the to-be-processed workpiece avoiding the micromirror which became a malfunction, it becomes possible to secure a predetermined | prescribed irradiation area and to use a laser processing apparatus continuously.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings. In all the drawings, even when the embodiments are different, the same or corresponding members are given the same reference numerals, and common descriptions are omitted.

[First Embodiment]

A laser processing apparatus in accordance with a first embodiment of the present invention will be described.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram for demonstrating the schematic structure of the laser processing apparatus concerning a 1st Example of this invention. It is explanatory drawing for demonstrating the structure of the slit of the laser processing apparatus which concerns on the 1st Example of this invention. 3 is a cross-sectional explanatory diagram for explaining the configuration and operation of the cross-sectional direction of the micromirror array of the laser processing apparatus according to the first embodiment of the present invention. 4 is a schematic plan explanatory diagram showing a state in which the micromirror array of the laser processing apparatus according to the first embodiment of the present invention is seen from the reflection surface side, and a planar explanation showing an example of an image on the workpiece for explaining the operation thereof. It is also. It is a schematic explanatory drawing for demonstrating an example of the image obtained by the imaging element of the laser processing apparatus which concerns on the 1st Example of this invention.

In FIG. 1, the laser processing apparatus 50 includes a laser light source 1 (light source unit), an illumination optical system 3, a digital micromirror device (DMD) 4 (micromirror array), a condenser lens 5, Wavelength selection mirror 6, objective lens 7, relay optical system 10, attenuation filter 11, second imaging element 12 (imaging element), second image processing unit 13 (deflection operation detection means) Controller 14 (light emitting control means), actuator driver 15, biaxial displacement actuator 16 (moving means), imaging optical system 17, first imaging device 18, first image processing unit 19 And a slit 25, an area controller 26, and warning means 27. And the laser processing apparatus 50 projects the laser beam 2A which has the predetermined light output and wavelength which formed the predetermined pattern on the sample 9 (workpiece), and the sample 9 by the light energy. ) To machine the surface. Examples of the processing by light energy include heating, melting, vaporization, cutting, exposure recording, and the like.

The laser light source 1 generates the laser beam 2 for processing the sample 9. The light output and the wavelength of the laser beam 2 are set to the light output and the oscillation wavelength at which the processing efficiency becomes good according to the wavelength characteristic of the light absorption of the material of the processed portion of the sample 9. Light emission control such as lighting, extinction, modulation, etc. of the laser beam 2 is performed by a control signal 101 generated by the controller 14 described later.

For example, in the case of processing a photoresist film masked on a glass substrate, such as a liquid crystal substrate, YAG laser (basic wavelength (lambda) 1 = 1.064 micrometer (micrometer)) is used as the laser light source 1, and 2nd, 3rd, 3rd It is possible to preferably employ four harmonics (wavelength λ2 = 532nm, λ3 = 355nm, λ4 = 266nm) for pulse oscillation with a pulse width of several nsec and a peak output of several MW.

The illumination optical system 3 consists of the optical system which makes the laser beam 2 formed by the laser light source 1 into the substantially parallel luminous flux with which the cross-sectional intensity distribution was uniform, and is arrange | positioned on the optical path of the laser beam 2. As the structure of such an illumination optical system 3, since various structures, such as a fly-eye lens, a diffraction element, an aspherical lens, and the Kaleido rod, are known, you may employ | adopt any structure as needed.

The slit 25 is arranged between the laser light source 1 and the DMD 4, and has an optical design such that only the laser beam 2 passing through the opening of the slit 25 is incident on the DMD 4. have.

The slit 25 is comprised from two components, the slit components 25A and 25B, as shown in FIG. These are mounted on an XY stage mechanism (not shown) and can be controlled individually by the motor in the XY axis direction, respectively, and simultaneously in the X0Y0 direction. These XY stage mechanisms realize control of changing the size of the opening of the DMD 4 or sliding the center position of the opening. At this time, the driving resolution is at least equal to the pixel size of the micromirrors constituting the DMD 4, and the movement range in the XY direction is any area within the DMD 4 that can be used by one laser irradiation. Even a small mirror is the range which can be irradiated independently.

Although the shape of an opening part is not specifically limited, In order to make the difference between the area of the irradiation area of the laser beam 2 and the area of a micromirror use area smaller, it is preferable to match with the arrangement shape of a micromirror as much as possible. That is, as long as the micromirrors are arranged in a rectangle, the openings are also rectangular and the micromirrors are arranged radially, and the openings are preferably radial.

When the control data is input, the opening and closing of the slit 25 is expanded and reduced accordingly, and control is performed such that the laser beam 2 is irradiated only to the input area.

In the DMD 4, which is a spatial modulation element, a plurality of movable mirror surfaces 4a (see Fig. 3) in which respective inclination angles can be independently switched on the movable mirror arrangement surface 4b are two-dimensional with almost no gaps. It is a micro mirror array.

The inclination angle of each movable mirror surface 4a is switched by the control signal 106 generated by the area controller 26 described later. When the on state is selected by the control signal 106, the movable mirror surface 4a becomes the on state mirror 4A inclined by the inclination angle Ø _A with respect to the movable mirror arrangement surface 4b. When the off state is selected by the control signal 106, the inclined angle becomes the off state mirror 4B inclined by Ø _{B in the} same manner.

In the on-state mirror 4A, the laser beam 2 is deflected as the laser beam 2A in the first direction toward the sample 9, and in the off-state mirror 4B, the laser beam 2 is the sample 9 Is deflected as the laser beam 2B in a second direction spaced apart from the?

In the first embodiment, as shown in Fig. 3, the first direction is a normal direction of the movable mirror arrangement surface 4b, and the second direction is an angle Ø _B with respect to the normal of the movable mirror arrangement surface 4b. An example in the case where the direction is inclined is described.

Here, the incidence direction of the laser beam 2 is assumed to be a direction different from the first direction. Incidentally, the inclination angles Ø _A and Ø _B are the inclination angles which sandwich the movable mirror arrangement surface 4b and are inclined in opposite directions, respectively. Accordingly, the following equations (1) and (2) are established.

θ _i = 2 × Ø _A. Formula (1)

θ _O = θ _i + 2 × Ø _B. Formula (2)

Here, angle (theta) _i is the incidence angle of the laser beam 2 with respect to the movable mirror arrangement surface 4b, and let it be an angle other than O degree.

The size of the movable mirror arrangement surface 4b is sufficiently larger than the beam diameter of the laser beam 2 whose cross-sectional intensity distribution is uniform by the illumination optical system 3, and each movable mirror surface 4a is formed of the laser beam 2. It is comprised smaller than the beam diameter.

The DMD 4 can adopt the same structure as that used for a projector etc., for example. That is, according to the MEMS (Micro Electrc Mechanical Systems) technology, the movable mirror surface 4a, which is about 10 micrometers (μm) in size and has a high-efficiency reflective surface due to the deposition of a metal film on the surface, for example, 800 It can be adopted that the array is arranged in an array of about 600 pieces, and each can be inclined at an inclination angle (Ø _A = Ø _B = 12 °) of about + 12 ° with respect to the movable mirror array surface 4b.

The size, shape of the cross section of the light beam of the laser beam 2, and the size of the movable mirror arrangement surface 4b can be any suitable shape and size depending on the processing type, the workpiece, and the like. 2) This configuration has a circular cross section of a beam diameter of Ø3 mm, and a configuration in which the size of the movable mirror arrangement surface 4b is about 8 mm x 6 mm can be adopted.

The condenser lens 5 and the objective lens 7 constitute a projection optical system for projecting the laser beam 2A onto the specimen 9 of the laser beams 2 irradiated onto the DMD 4, The movable mirror arrangement surface 4b and the processing surface of the sample 9 are provided so as to be in an air space relationship. In addition, the movable mirror arrangement surface 4b and the processing surface of the sample 9 may be substantially perpendicular to the optical axis. The processed surface may be a range within which the processed portion may be allowed even if it is inclined with respect to the optical axis, and the movable mirror arrangement surface 4b may be allowed to be inclined within the depth of focus determined by the size of one mirror surface and the NA of the projection optical system.

In order to form such a projection optical system, for example, the objective lens 7 employs an optical system whose image side is infinitely circular, and the object-side focus position is on the sample 9. As the condensing lens 5, the lens designed infinity similar to the objective lens 7 may be disposed at the position where the object-side focus position is on the movable mirror surface 4a.

That is, by this projection optical system, an image pattern of an appropriate magnification corresponding to the arrangement of the state mirror 4A projected onto the sample 9 by the laser beam 2A reflected from the on state mirror 4A is obtained from the sample ( 9) to be formed on.

On the other hand, in the vicinity of the sample 9, a visible light illuminator 8 for illuminating the sample 9 image with visible light is provided. As the visible light illuminator 8, for example, a halogen lamp or the like in which a wavelength is distributed from a relatively long wavelength region to an infrared region of visible light can be employed.

In addition, on the optical path between the condenser lens 5 and the objective lens 7, almost 100% of the wavelength light of the laser beam 2A is transmitted and almost 100% of the light in the visible wavelength region of the visible light illuminator 8 is transmitted. The wavelength selection mirror 6 which reflects is arrange | positioned.

Therefore, when the illumination light irradiated by the visible light illuminator 8 is scattered and reflected from the sample 9 to form the illumination reflection light 20, the illumination reflection light 20 is collected by the objective lens 7, and the projection optical system The optical path is reversed to reach the wavelength selective mirror 6, reflected by the wavelength selective mirror 6, and diverged from the projection optical system.

On the optical path of the illumination reflection light 20 branched by the wavelength selective mirror 6, the imaging optical system 17 and the 1st imaging element 18 are arrange | positioned in the order which follows an optical path.

The imaging optical system 17 is an optical system for forming an image of incident light on a predetermined imaging surface. For example, an optical system in which an object plane is set at an infinite circle is employed. In the case of the first embodiment, since the illumination reflection light 20 is incident light, the image of the sample 9 is formed on the image forming surface.

The 1st imaging element 18 is an imaging element which consists of CCD etc. in which the imaging surface is arrange | positioned at the imaging surface of the imaging optical system 17, for example. The first image processing unit 19 is electrically connected to the first image processing unit 19 to perform photoelectric conversion on the image projected by the imaging optical system 17 and to transmit the image to the first image processing unit 19 as image data 105.

The first image processing unit 19 is electrically connected to the area controller 26 and sends data 102 indicating the on-off state of each movable mirror surface 4a of the DMD 4 to the area controller 26. It is possible.

The area controller 26 (irradiation area control means) is configured to determine a portion of the portion that needs to be processed on the sample 9 in accordance with the image data 105 sent from the first imaging device 18 through the first image processing unit 19. The position is calculated, the movable mirror surface 4a corresponding to the site is selected from the array arrangement to be the on state mirror 4A, and the movable mirror surface 4a corresponding to the other site is the off state mirror 4B. To generate a control signal 106 for In addition, the size of the matrix of the data 102 received from the first image processing unit 19 is determined, and the control signal 106 is transmitted to the DMD 4 for control.

Here, the matrix refers to, for example, a region determined on the basis of a micromirror when the area of the sample 9 to be irradiated is projected by the DMD 4 at an optically conjugate position.

In addition, the area controller 26 manages the degree of deterioration of each micromirror constituting the DMD 4 based on the information from the first image processing unit 19 and the second image processing unit 13 described later, The mode of use of the DMD 4 is switched accordingly. The use mode includes a normal mode and a deterioration response mode.

While the DMD 4 is not deteriorated, the normal mode is used, and the data 102 is transmitted to the DMD 4 as it is in the size of the matrix. However, upon receiving the area dividing command 109 from the controller 14, the process shifts to the degradation-corresponding mode, in which case the matrix of data 102 is divided. That is, the defect area on the sample 9 is divided. Then, the size of the matrix is reduced by division, and the warning command 110 is sent to the warning means 27.

As long as the image processing of the area controller 26 can calculate the site | part which needs processing from the image of the sample 9, you may use what kind of image processing. For example, by setting a threshold value corresponding to the luminance difference between the processed portion and the defective machining or the unprocessed portion, the image on the sample 9 is binarized and compared with the shape of the predetermined portion to be processed, Image processing that calculates the position of the defective machining or the unprocessed portion that requires processing can be employed.

For example, it is assumed that the image after binarization is distributed in the range shown by the diagonal lines as shown in Fig. 4B, so that the patterns 22a and 22b can be obtained. Here, the irradiation range of the laser beam 2 is shown as a square for easy viewing. The shape of the actual irradiation range may be another shape such as a circle or a rectangle.

On the other hand, the arbitrary area on this image corresponds to the checkerboard-shaped projection area | region where the laser beam 2A each reaches | attains with the on-state mirror 4A corresponding to the array type arrangement of the movable mirror surface 4a. 21). For example, the center coordinates of each region and the surface number of the movable mirror surface 4a for guiding the laser beam 2A to each projection region 21 are stored as corresponding array data, respectively.

On the other hand, the information of the part to be processed is also given for each projection area 21, and stored in the area controller 26 as information on whether or not the areas 23a and 23b without images are areas to be processed, for example. It is.

Therefore, by comparing and judging the image distribution for each projection area 21 and the information of whether or not it is a part to be processed, the machining failure and the unprocessed part are determined. If it is determined that the regions 23a and 23b are unprocessed regions even though the regions 23a and 23b are to be processed, the inclination angles of the movable mirror surfaces 4a and 4a corresponding to the regions 23a and 23b are switched to turn on the on-state mirror 4A. 4A), a control signal 106 is generated.

In this example, the movable mirror surfaces 4a corresponding to the regions 23a and 23b are the movable mirror surfaces 4C and 4D in Fig. 4A, respectively.

The relay optical system 10 is an optical system for projecting the laser beam 2B onto the second imaging element 12 through an attenuation filter 11 that attenuates the laser beam 2B to an appropriate amount of light in accordance with the sensitivity of the second imaging element 12. It is provided so that the movable mirror surface 4a and the imaging surface of the 2nd imaging element 12 may be in air space relationship.

As the attenuation filter 11, for example, a reflective attenuation filter in which a metal film such as aluminum is deposited on glass, a damping filter using a dielectric multilayer film in which a dielectric is laminated, and the like can be preferably used.

The relay optical system 10 and the attenuation filter 11 constitute the detection optical system of the first embodiment.

The 2nd imaging element 12 is an imaging element which consists of CCD etc. in which the imaging surface is arrange | positioned on the upper surface of the relay optical system 10, for example. The second image processing unit 13 is electrically connected to the second image processing unit 13 to perform photoelectric conversion on the image projected by the relay optical system 10 and to transmit the image to the second image processing unit 13 as the image data 103.

The second image processing unit 13 specifies that the off state mirror 4B is one of the movable mirror surfaces 4a in accordance with the image data 103 sent from the second imaging element 12, and the data 104 ) Is sent to the controller 14 electrically connected.

Image processing for specifying the off state mirror 4B is, for example, less than the luminance of the laser beam 2B reflected by the off state mirror 4B and transmitted through the relay optical system 10 and the attenuation filter 11. Set a slightly lower threshold to binarize the image picked up by the second imaging element 12, and perform image processing to correlate the region above the threshold with the arrangement position of the movable mirror surface 4a on the DMD 4; It can be adopted.

For example, when the processing corresponding to the patterns 22a and 22b of FIG. 4B is being performed, the movable mirror surface 4a is moved to the off state mirror 4B in other areas during normal processing. As a result, in the second imaging device 12, a pattern 44 (see FIG. 5A) in which the patterns 22a and 22b are inverted is obtained. Conversely, when the pattern 44 is obtained, it is determined that the movable mirror surface 4a at the position corresponding to the pattern 44 is the off state mirror 4B.

The controller 14 is a control unit for performing overall control of the laser processing apparatus 50, and is electrically connected to the area controller 26, the second image processing unit 13, the laser light source 1, and the actuator driver 15, respectively. Is connected.

The main control of the controller 14 consists of light emission control, deflection motion detection control, and irradiation area movement control.

The light emission control is performed in a processing mode that is turned on with a laser power (light output) required for processing the sample 9, and the laser beam 2 reaches the sample 9 so as not to cause a change in the sample 9. The pre-luminescence mode which emits light at low power is switched. And instead of the pre-light emitting mode by the laser light source 1, the reflective optical element, such as a half mirror, is provided between the laser light source 1 and the illumination optical system 3, and the light source low enough output with respect to lasers, such as an LED, May be provided so as to irradiate the DMD 4 by the laser light source 1 so as to emit light.

In the processing mode, for example, light emission is controlled so as to perform pulse oscillation with a peak output of P ₂ and an oscillation period of several nsec. Further, in the pre-light emission mode, for example, the light emission is controlled so that the peak output performs pulse oscillation similar to P ₁ .

In the first embodiment, the deflection motion detection control compares the data 102 received through the area controller 26 with the data 104 from the second image processing unit 13 to deflect the DMD 4. It is the control which performs irradiation area movement control when it determines an operation | movement state and detects deflection operation defect. Therefore, the controller 14 of the first embodiment also serves as a deflection motion detecting means.

Irradiation area movement control is control which drives the 2-axis displacement actuator 16 through the actuator driver 15, and moves the DMD 4 two-dimensionally along the surface of the movable mirror arrangement surface 4b.

And the detection optical system, the 2nd imaging element 12, the 2nd image processing part 13, and the controller 14 comprise the malfunction malfunction element detection means.

 The biaxial displacement actuator 16 (spatial modulation element slide mechanism) has the inclination angle of the movable mirror surface 4a with respect to the laser beam 2 in a plane along the movable mirror arrangement surface 4b of the DMD 4. It is a moving means for moving so that it does not change, and it is driven in two-axis direction by receiving the movement control signal 114 from the actuator driver 15. As shown in FIG. The minimum amount of movement in the movement direction is set so that at least one unit of the movable mirror surface 4a can be accurately moved.

In addition, the biaxial displacement actuator 16 sets the slide range so that the irradiation position similar to that of the upper left mirror of the DMD 4 can also be irradiated with the micro mirror at the lower right on the work surface.

The kind of actuator can employ | adopt an appropriate thing. For example, the mechanism which combined the actuator driven by a axial direction by a ball screw feed mechanism, a linear motor, etc. can be employ | adopted.

The actuator driver 15 is a driver that generates the movement control signal 114 for driving the biaxial displacement actuator 16 in accordance with the control signal 100 from the controller 14.

The warning means 27 receives the warning command 110 from the area controller 26 and uses a dialog, a signal tower, or the like, so that the DMD 4 is deteriorated for the user of the laser processing apparatus 50. Notify. The information of the warning instruction 110 which was received once is maintained until the DMD 4 is replaced, and continues to warn in the meantime. After replacing the DMD 4, the information of the warning command 110 is reset.

Next, the operation of the laser processing apparatus 50 of the first embodiment will be described.

First, the laser processing process by a normal mode is demonstrated.

In order to process by the laser processing apparatus 50, the power supply switch which is not shown in figure is input, an appropriate initialization is performed, and the sample 9 is set.

When the DMD 4 is initialized, the inclination angle of each movable mirror surface 4a is set to Ø _B shown in FIG. 3 and set to the off state mirror 4B.

When the visible light illuminator 8 is turned on, as shown in FIG. 1, the illumination light is reflected by the sample 9, and the illumination reflection light 20 made of visible light is condensed by the objective lens 7. The light is reflected by the wavelength selective mirror 6 at almost 100%, is incident on the imaging optical system 17, and an image of the sample 9 is imaged on the imaging surface of the first imaging device 18.

The image data 105 is sent from the first image pickup device 18 to the first image processing unit 19, and information of a portion to be processed can be obtained from the image of the sample 9.

It is assumed that the images of the patterns 22a and 22b shown in Fig. 4B are obtained and that the regions 23a and 23b are the defective machining parts from the information stored in the area controller 26.

For example, the defective processing portion is a short portion of the circuit pattern or an unnecessary pattern protruding from it, and it is necessary to perform processing such as heating and sublimation to eliminate the short portions and unnecessary patterns of the patterns 22a and 22b. .

Therefore, in order to irradiate the laser beams 2A to the areas 23a and 23b, the area controller 26 controls the control signal (with the movable state 4a corresponding to these areas as the on state mirror 4A). 106 is sent to the DMD 4. In addition, the setting information of the on state mirror 4A is sent from the first image processing unit 19 to the area controller 26 as data 102.

Hereinafter, the movable mirror surface 4a used as the on state mirror 4A will be described as being the movable mirror surfaces 4C and 4D in FIG. 4A.

When the DMD 4 receives the control signal 106, the movable mirror surfaces 4C and 4D are set at the inclination angle Ø _A to be the on state mirror 4A. It is assumed here that the movable mirror surface 4C has reached the end of its service life, which causes malfunction and is not controlled to an accurate inclination angle.

On the other hand, the laser light source 1 is shaped so that the laser beam 2 is turned on by the controller 14 and the cross-sectional intensity is made uniform by the illumination optical system 3, and the pre-light emitting mode is applied to the DMD 4. Investigate with. For example, it irradiates to the irradiation area 24A shown in FIG. The laser beams 2A and 2B are divided according to the inclination angles of the movable mirror surfaces 4a. In the first embodiment, the movable mirror surface 4C is inferior in operation and becomes the off state mirror 4B.

Since the movable mirror surface 4D operates normally, it is set to the on state mirror 4A.

Therefore, the laser beam 2A deflected by the movable mirror surface 4D is focused by the condensing lens 5, is almost 100% transmitted through the wavelength selective mirror 6, and is condensed by the objective lens 7. It reaches on the sample 9, and is irradiated to the area | region 23b of FIG. 4 (b).

On the other hand, the laser beam 2B reflected by the off-state mirror 4B passes through the relay optical system 10 and the attenuation filter 11 and is projected onto the second imaging element 12, for example, FIG. An image similar to the pattern 45 shown in 5 (b) is picked up and sent to the second image processing unit 13 as the image data 103.

The second image processing unit 13 performs image processing on this image, specifies the movable mirror surface 4a serving as the off state mirror 4B, and sends it to the controller 14 as data 104.

The controller 14 compares the data 102 received through the area controller 26 with the data 104 from the second image processing unit 13, thereby making the area 46 to be the on-state mirror 4A. It is determined that the movable mirror surface 4C corresponding to) is causing a malfunction (deflection motion detection control).

As a result of this determination, the controller 14 performs irradiation area movement control. The movement direction and the movement amount may be set as long as the detected malfunctioning part is excluded. When the state of the off state mirror 4B is normal by repeating the above steps, the pre-light emission operation is terminated, and the controller 14 sends a control signal 101 to the laser light source 1, Start the machining process.

In the processing step, the regions 23a and 23b of FIG. 4B are heated and sublimed, and the patterns 22a and 22b are normally restored.

The above is the laser processing process by a normal mode. However, as the deterioration progresses, no matter how the data is moved from the second image processing unit 13 obtained in the pre-light emission mode and the data 102 from the first image processing unit 19, the irradiation is performed. When the controller 14 detects that the deteriorated micromirror enters the area to be used, it is possible to switch to the deterioration response mode.

Hereinafter, the deterioration mode will be described with reference to FIGS. 6 and 7.

6 (a) is a schematic diagram showing the area to be used for the micromirror corresponding to the rectangular irradiated area (defects, etc.) in the micromirror area (the outermost frame of the matrix) of the DMD 4, and FIG. b) is a schematic diagram showing a state of the DMD 4 in which one deterioration has occurred in the center portion of the DMD 4. 7 is a schematic diagram corresponding to the DMD 4 side when the area to be irradiated is divided into two rectangular areas without deterioration up and down.

Here, the area to be irradiated and the DMD 4 corresponding thereto are in an optically conjugate position relationship, and therefore, the drawings are expressed as a matrix on the DMD 4 side.

When the controller 14 receives the data 102 through the area controller 26, the controller 14 performs division determination. Since the first mode is the normal mode, the division determination is NO, and the control signal 107 and 108 are transmitted to the controller 14 and the slit 25 as it is.

Next, the controller 14 performs the deflection operation detection control, irradiates a laser beam to the DMD 4 by the data 102 received through the area controller 26 and the pre-light emitting mode, and thereby the second imaging device 12. Image is captured by the second image processing unit 13 and the deteriorated micromirror is compared with the specified data 104, thereby optimizing the position of the DMD 4 that does not use the deteriorated micromirror. Search for the location of use. However, if the deteriorated micromirrors are distributed at this time as shown in Fig. 6 (b), the deteriorated micromirrors cannot be avoided even if the DMD 4 is slid, resulting in the inability to see the optimum use position. In this case, it is determined that the transition from the normal mode to the deterioration response mode is made.

The controller 14 notifies the area controller 26 of the area division command 109 together with the identification number in the deterioration response mode. The area controller 26 which received the area division command 109 divides the matrix of the data 102 supported by the first matrix and the second matrix into two, for example, as shown in FIG. At this time, the dividing method divides the area to be used into a rectangular shape, for example, up and down. In the case of projecting toward the DMD 4 side, the longitudinal and horizontal directions can be divided into two areas of 17 × 8 of the micromirror. Therefore, the process of dividing the area | region of the sample corresponding to this area | region is performed based on 17x8 micromirror area | regions on the DMD side.

Here, the division method is preferably a method in which the area is divided into two parts as much as possible. For example, the method of obtaining the center position of a surface, and dividing the center into upper and lower sides, right and left, and inclination etc. can be considered. Each unique identification number is assigned and retained.

At the same time, the warning command 110 is also notified to the warning means 27. The warning means 27 which received the warning command 110 warns the operator of the laser processing apparatus 50 that the DMD 4 is deteriorated on a monitor, a signal tower, or the like. In this case, the timing of the warning is not limited to the above. For example, the number of times the DMD 4 is slid during the deflection motion detection control may be counted to warn the user when the number of slides is more than the specified number of times.

Next, the area controller 26 first transmits the first matrix to the controller 14 as control data. Here, deflection motion detection control is performed again to find the optimum use position based on the usable area of the DMD 4. In this case, since there are 17 x 8 usable areas vertically and horizontally above the deteriorated mirror, irradiation can be performed using this area, and the controller 14 controls the irradiation area movement of the DMD 4. In this way, the actuator driver 15 is instructed and the biaxial displacement actuator 16 is controlled to move the DMD 4 downward by one minute mirror. Then, the processing is performed in the above-described flow.

When the irradiation of the laser beam 2 is completed without any problem, the controller 14 requests data of the following matrix from the area controller 26. In response to the request, the area controller 26 transmits the data of the second matrix to the controller 14. Here, deflection motion detection control is performed similarly to the first matrix. And if there is no problem, irradiation area movement control is performed. However, if a new deteriorated mirror is generated by the laser light irradiation in the pre-luminescence mode or the optimal use position cannot be seen again according to the shape of the defective portion, the second matrix is separated in the same step. The area is divided again.

The above process is repeated until all the areas of the data 102 are completed.

In this way, even when the DMD 4 is slid, even when the deteriorated micromirror is inevitable, the laser processing apparatus 50 can be used continuously. Also, by alerting the operator of the deterioration of the DMD 4, the operator can prepare for maintenance before the laser processing apparatus 50 is disabled, thereby reducing the down time of the laser processing apparatus 50. Can be.

Incidentally, in the deflection motion detection control in the first embodiment described above, it is determined in units of one minute mirror whether or not it is an optimal use position. However, only the deterioration of one micromirror does not substantially affect laser processing by the diffraction phenomenon. Therefore, when the number of micromirrors with malfunctions exceeds a predetermined number per unit area, an area composed of the plurality of micromirrors is determined as the deterioration area, and the optimum use position is determined when the deterioration area is included in the irradiation area. You may judge that it is not.

Even if the micromirror is broken by the unit, it is conceivable that the machining does not affect the machining. Therefore, the service period of the DMD 4 can be further extended by doing this.

Incidentally, the determination of the transition to the degradation-corresponding mode in the present embodiment is performed based on whether or not the optimum use position is found by the deflection motion detection control, but the number of deteriorated micromirrors set as a reference in advance is set. The number of mirrors may be managed so as to be in the normal mode until the deterioration of the micromirrors larger than the preset threshold occurs, and the transition to the deterioration corresponding mode may be made when the deteriorated micromirrors exceeds the threshold.

In addition, the total or partial reflection luminance of the DMD 4 in the normal mode may be grasped in advance, and it may be possible to switch to the degradation-corresponding mode when the reflection luminance falls below a preset threshold.

In addition, the laser irradiation time or the number of laser irradiation times for the DMD 4 may be managed, and the transition to the degradation-corresponding mode may be made at a time point exceeding the preset laser irradiation time or the laser irradiation number.

In addition, in the above-described first embodiment, the normal mode is defined as " state usable without region division by the area controller 26 " and the degradation correspondence mode is defined as " state usable by division of an area " The normal mode may be referred to as "state usable without sliding the DMD 4", and the deterioration-response mode may be referred to as "state usable by sliding the DMD 4".

In the present embodiment, the irradiation area movement control in the deflection motion detection control is a movement operation of the DMD 4 using the biaxial displacement actuator 16, but instead the orthogonal to which the sample 9 is mounted. A two-axis moving stage capable of moving in two axes, and controlling the two-axis moving stage to relatively move the DMD 4 and the sample 9, or two orthogonal to the laser processing apparatus 50 as a whole. By mounting in the gantry apparatus which can move to an axial direction, you may move the DMD 4 and the sample 9 relatively, and you may perform irradiation area movement control. That is, the control which switches the micromirror which is the control object of the DMD 4 should just be used.

And each Example of this invention demonstrates the laser repair apparatus which extracts the defect area | region on a board | substrate by imaging, and corrects it according to the shape of the defect area | region in the process of manufacturing board | substrates, such as a liquid crystal display device, as an example. However, the present invention can also be applied to a laser processing apparatus that does not have an imaging system for defect extraction. That is, the imaging optical system 17, the first imaging device 18, the first image processing unit 19, the wavelength selection mirror 6, and the like are omitted, and instead the data of the processing site is input to the area controller 26. Install the processing information storage unit. And the data of a process site | part may be input into the area controller 26 from the process information storage part.

As mentioned above, although each Example of this invention was described referring drawings, the laser processing apparatus to which this invention is applied is not limited to each above-mentioned Example etc. as long as the function is performed, It goes without saying that the device may be a system composed of a plurality of devices or an integrated device, or a system in which processing is performed through a network such as a LAN or a WAN.

That is, the present invention is not limited to the above-described embodiments and the like, and various configurations or shapes can be taken without departing from the gist of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram for demonstrating schematic structure of the laser processing apparatus which concerns on 1st Example of this invention.

It is explanatory drawing for demonstrating the structure of the slit of the laser processing apparatus which concerns on the 1st Example of this invention.

3 is a cross-sectional explanatory diagram for explaining the configuration and operation of the cross-sectional direction of the micromirror array of the laser processing apparatus according to the first embodiment of the present invention.

4 is a schematic plan explanatory diagram showing a state in which the micromirror array of the laser processing apparatus according to the first embodiment of the present invention is seen from the reflection surface side, and a planar explanation showing an example of an image on the workpiece for explaining the operation thereof. It is also.

It is a schematic explanatory drawing for demonstrating an example of the image obtained by the imaging element of the laser processing apparatus which concerns on the 1st Example of this invention.

6 is a diagram schematically showing an example of used / unused and deteriorated / normal micromirrors.

7 is a diagram illustrating an example in which a matrix of data is divided into two.

[Explanation of symbols on the main parts of the drawings]

(1) laser light source (light source)

(2, 2A, 2B) laser beam

(3) illumination optical system

(4) DMD (Micro Mirror Array)

(4a) movable mirror surface (movable reflecting surface)

(4b) movable mirror array surface

(4A) on state mirror

(4B) off-state mirror

(4C, 4D) Movable Mirror Surface

(5) condensing lens (projection optical system)

(6) wavelength selection mirror

(7) objective lens (projection optical system)

(8) visible light

(9) Sample (workpiece)

(10) relay optical system (detection optical system)

(11) attenuation filter

(12) Second imaging device (imaging device)

(13) second image processing unit (deflection operation detecting means)

(14) controller (exposure control means)

(15) Actuator driver

(16) 2-axis displacement actuator (moving means)

(17) Imaging optical system (detection optical system)

18. First imaging device

(19) first image processing unit

20 lights reflected light

21 projection area

22a, 22b pattern

(23a, 23b) areas without images

(24A, 24B, 24C, 24D) irradiation area

25 slits

(25A, 25B) Slit Parts

(26) zone controller

(27) warning means

44, 45 pattern

46 areas

50 laser processing equipment

(100, 101) control signal

(102, 104) data

(105) image data

(106, 107, 108) control signal

(109) Zone division command

(110) Warning instruction

114 movement control signal

200 solid lines

Claims (10)

A space modulating element configured by arranging a plurality of micro movable elements to irradiate a workpiece with a laser beam emitted from a laser light source in a desired shape; A projection optical system arranged such that the spatial modulation element and the workpiece are in a conjugate position; Irradiation area control means for controlling the operation of the spatial modulation element in accordance with a preset irradiation area of the irradiation; Malfunction-free element detection means for detecting a micro-movement element that is malfunctioning among the micro-moving elements constituting the spatial modulation element; In the case where the position of the micro-moving element detected to be inoperable by the inferior element detecting means overlaps with the irradiation area, the workpiece is irradiated into a plurality of times using an area in which the inoperation is not detected. Control means for controlling to perform Laser processing apparatus provided with. The method of claim 1, And moving means for moving the workpiece relatively to the irradiating optical system or moving the spatial modulation element relatively to the workpiece, When the control means divides the irradiation area and performs irradiation by dividing into a plurality of times using an area in which the operation failure is not detected, the control means relatively moves the irradiation optical system and the processing object. Or, by controlling the spatial modulation element to move relative to the workpiece and to irradiate. The method of claim 1, An imaging optical system for imaging the workpiece, It further comprises an imaging element arranged at an image position of the imaging optical system, The said irradiation area control means extracts the said irradiation area | region by image processing according to the image of the to-be-processed object imaged by the said imaging element, and sets previously. The method of claim 2, Moving means for moving the spatial modulation element relative to the workpiece, A laser processing apparatus, comprising: a moving means for moving the space modulating element in a plane along the movable mirror arrangement surface, and a space modulating element slide mechanism. The method of claim 1, The said control means is a laser processing apparatus which irradiates into the said to-be-processed object in multiple times by switching from a normal mode to a degradation-response mode. The method of claim 5, And said control means makes it possible to transition to said deterioration-corresponding mode when the number of small movable elements, which are malfunctions, detected by said malfunctioning element detection means exceeds a predetermined number per unit area. The method of claim 5, And said control means makes it possible to transition to said deterioration-corresponding mode when a small number of micro-moving elements which are malfunctions detected by said malfunctioning element detection means have exceeded a predetermined number. The method of claim 5, And said control means makes it possible to transition to said deterioration-corresponding mode when the total or partial reflection luminance of said spatially modulated element previously obtained is lower than a predetermined threshold value. The method of claim 5, And said control means makes it possible to transition to said degradation-corresponding mode when the laser irradiation time or the number of laser irradiation to said spatially modulated element acquired in advance exceeds the preset laser irradiation time or the number of laser irradiation. A space modulating element composed of a plurality of micro movable elements arranged so as to irradiate a workpiece with a laser beam emitted from a laser light source in a desired shape, and a projection optical system arranged such that the space modulating element and the workpiece are in a conjugate position Computer of laser processing apparatus to include, To control the operation of the spatial modulation element according to a preset irradiation area of the irradiation, Detecting the micro movable element which is malfunctioning among the micro movable elements which comprise the said space modulation element, In the case where the position of the micro-moving element detected that the operation failure is overlapped with the irradiation area, the laser is controlled to perform irradiation by dividing the workpiece into a plurality of times using an area where the operation failure is not detected. Processing method.

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