KR101513107B1 - Adjusting apparatus laser beam machining apparatus adjusting method and adjusting program - Google Patents

Abstract

The present invention relates to an adjusting device, a laser machining device, an adjusting method, and an adjusting program, and an object thereof is to automatically and automatically adjust the irradiation of the space-modulated light.

According to the present invention, when the control section 113 designates the calibration pattern on the DMD 106, the LED light from the LED light source 116 is spatially modulated by the DMD 106 and irradiated onto the work 102 . The CCD camera 112 picks up the workpiece 102. The control unit 113 receives the captured image and calculates a conversion parameter for converting an output pattern and a calibration pattern occurring on the image in accordance with the calibration pattern. When the laser beam from the laser oscillator 103 is subjected to spatial modulation by the DMD 106 and irradiated to the workpiece 102 in accordance with the irradiation pattern designated by the operation unit 114 or the like, Adjust the irradiation of the laser beam.

Description

ADJUSTING APPARATUS, LASER BEAM MACHINING APPARATUS, ADJUSTING METHOD, AND ADJUSTING PROGRAM <br> <br> <br> Patents - stay tuned to the technology ADJUSTING APPARATUS,

The present invention relates to a technique for adjusting the irradiation of light that has been spatially modulated by a spatial modulation element.

Conventionally, a laser processing apparatus for processing a workpiece by irradiating a laser beam to the workpiece is used. There are various kinds of processing such as drawing of letters and drawings, exposure, and repair (repair) in the manufacturing process of a substrate. The substrate may be a flat panel display (FPD) such as a liquid crystal display (LCD) or a plasma display panel (PDP), a semiconductor wafer, a multilayer printed circuit board and so on.

Such a laser machining apparatus is provided with a mechanism for irradiating the laser light in a specified position, direction and shape. Conventionally, a slit or the like has been used as this mechanism. Recently, a space modulation device such as a DMD (Digital Micromirror Device) in which micromirrors are arrayed is used as this mechanism. The spatial modulation element is also referred to as a spatial light modulator (SLM).

However, as a result, the position, direction and shape of the laser beam actually irradiated with the designated position, direction and shape may be different from each other. This is because there are a plurality of optical components on the optical path from the laser light source to the workpiece, and are influenced by non-uniformity of these optical components, misalignment of mounting position, misalignment of mounting direction, and the like.

Therefore, it is necessary to calibrate and adjust the method of irradiating the laser light so that the specified position, direction and shape match the position, direction and shape of the laser light actually irradiated.

The term "calibration" is sometimes used to mean "calibration ", but hereinafter," calibration " Further, unless otherwise stated, "adjustment" means adjustment according to the result of calibration.

Patent Literatures 1 to 3 disclose conventional techniques for adjusting the irradiation of laser light.

The laser processing apparatus described in Patent Document 1 calculates coordinate positions on an image of a processing pattern to be irradiated with a laser beam and coordinate positions on an image of a point irradiated with the laser beam to calculate the position deviation on both sides. Then, the stage is moved by converting the position deviation amount into a correction amount for moving the stage, and the position of the processing pattern is adjusted to coincide with the irradiation position of the laser beam.

However, in Patent Document 1, only the adjustment of the positional deviation in the X direction or the Y direction is described, and there is no description about scale conversion such as abnormal rotation, enlargement or reduction, or irregularity of the shape.

In the specimen observation system of Patent Document 2, a predetermined type of abnormal rotation or irregularity is considered. This system is a configuration in which a laser scanning device and an image acquisition device are mounted on a microscope. In this system, the irradiation position of the laser beam irradiated by the laser scanning device is measured from the image acquired by the image acquisition device. Calibration and adjustment are performed based on the information indicating the difference between the irradiation position obtained by this measurement and the irradiation designation position of the laser light irradiation instructed to the laser scanning device.

In this system, four factors regarding the difference between the irradiation position and the irradiation designation position are considered, and an adjustment method according to these factors is taken. For example, misalignment or unsteady rotation of the optical axis of the optical system of each of the image acquisition device and the laser scanning device is offset by a control for correcting the deflection operation of the deflection mirror for deflecting the laser beam.

Patent Document 3 discloses a teaching method for aligning the focal point position of a YAG laser beam to a laser machining point of a workpiece in a YAG laser processing machine. In this method, the Z-directional calibration of the YAG laser light in the optical axis direction and the X- and Y-directional calibration perpendicular to the Z-direction are performed.

For the calibration in the Z direction, slit light for measurement is used which is irradiated on a workpiece in an inclined direction with respect to the Z axis and viewed as a line parallel to the X axis on the workpiece. Calibration data in the Z direction is obtained from the relationship between the movement in the Z direction of the laser machining head and the Y coordinate of the slit light in the image picked up by the workpiece. Based on this data, correction in the Z direction for positioning the focal point of the YAG laser light on the surface of the workpiece is performed.

The correction in the X-Y direction is performed after the correction in the Z direction. More specifically, the laser processing head moves to the origin in the tool coordinate system (XYZ coordinate system), the laser light is irradiated by one shot, the bead trace formed by the irradiation is captured, The coordinates of the bead traces at the coordinates are obtained. Similarly, the laser machining head moves in order to the X-axis defining point on the X-axis and the Y-axis defining point on the Y-axis in order to irradiate the laser beam, capture the image, and obtain coordinates .

The transformation matrixes from the tool coordinate system to the pixel coordinate system are obtained using the coordinates in the tool coordinate system and the coordinates in the pixel coordinate system, which are coordinate systems of the image. This transformation matrix represents a combination of translational and rotational movement.

By the inverse transformation of the transformation by this transformation matrix, the coordinate of the detection point indicated by the pixel coordinate system is converted into the tool coordinate system. Then, the correction amount in the tool coordinate system is calculated, and the laser machining head moves in the X-Y direction by the correction amount.

[Patent Document 1] Japanese Patent Application Laid-Open No. 6-277864

[Patent Document 2] Japanese Patent Application Laid-Open No. 2004-109565

[Patent Document 3] Japanese Patent Application Laid-Open No. 2000-263273

The above-described Patent Documents 1 to 3 all describe a calibration and adjustment method when the irradiated laser beam is not subjected to spatial modulation. In addition, calibration and adjustment of light irradiation through a spatial modulation element has been performed by hand by man so far.

According to one aspect of the present invention, there is provided an adjustment device for adjusting irradiation of an object, which is spatially modulated by a spatial modulation element, according to a designated input pattern. Wherein the adjustment device includes: a take-in portion that receives an image of the object irradiated with light that has been spatially modulated by the spatial modulation element; an output pattern that corresponds to the input pattern on the image; And an adjustment section for adjusting the irradiation of light to the object in accordance with the designated irradiation pattern based on the conversion parameter calculated by the calculation section when the calibration pattern is used as the input pattern do.

According to another aspect of the present invention, a laser processing apparatus is provided. The laser processing apparatus includes an optical system for guiding laser light emitted from a laser light source onto an object, a spatial modulation element provided on an optical path from the laser light source to the object to space-modulate incident light, Wherein the laser light is used as light to be irradiated on the object in accordance with the irradiation pattern and the irradiation of the laser light with respect to the object is adjusted by the adjustment device to process the object.

According to another aspect of the present invention, there is provided a method of causing a computer to realize the adjustment device, and a program causing the computer to function as the adjustment device. The program is stored in a computer-readable storage medium.

In any of the above-described modes, irradiation of light to the object is adjusted based on the calculated conversion parameter. Therefore, compared with the case in which the difference between the specified irradiation pattern and the actually irradiated light pattern is not adjusted, it is reduced.

According to the present invention, since the irradiation of the light that is spatially modulated by the spatial modulation element is automatically adjusted in accordance with the conversion parameter, more accurate irradiation can be realized.

Further, according to the present invention, since the conversion parameter is calculated from one calibration pattern, it is sufficient to irradiate light only once to obtain the conversion parameter, and it is not necessary to repeat the irradiation and the mechanical movement of the structure as in the conventional method. Therefore, according to the present invention, it is possible to efficiently perform calibration and adjust irradiation of light.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings showing the different embodiments, the same reference numerals are given to the components corresponding to each other, and the description is omitted.

Hereinafter, the first embodiment will be described first, and the second to eighth embodiments in which the first embodiment is modified will be described. The first to eighth embodiments are all examples in which the present invention is applied to adjusting the irradiation of the laser beam in the laser processing apparatus. Next, the ninth embodiment will be described as an example in which the present invention is applied to adjusting the irradiation of light by the projector, and finally, other modified examples will be described.

Fig. 1 is a schematic view showing a configuration of a laser machining apparatus in the first embodiment. Fig. In the second to eighth embodiments, a laser processing apparatus having the same configuration as that of Fig. 1 is used.

1 is a device for processing a workpiece 102 mounted on a stage 101 by means of laser light emitted from a laser oscillator 103. The laser processing device 100 shown in Fig. The laser machining apparatus 100 performs predetermined machining on the workpiece 102, such as melting, cutting, printing of pictures or characters, exposure, or repair (repair) of a circuit pattern. In order to simplify the following description, it is assumed that the upper surface of the stage 101 is perpendicular to the vertical direction.

The workpiece 102 may be an FPD substrate, a semiconductor wafer, a laminated printed substrate, or other common samples.

The laser light emitted from the laser oscillator 103 passes through the half mirror 104, is reflected by the mirror 105, and is incident on the DMD 106.

The DMD 106 is a spatial modulation element in which micromirrors are arranged in a two-dimensional array. The inclination angle of the micromirror can be switched into at least two types. The mirror state when the tilt angle is the first angle and the second angle is hereinafter referred to as "on state" and "off state", respectively.

The DMD 106 independently switches the inclination angles of individual micromirrors, that is, individual micromirror states, based on an instruction from the control unit 113, which will be described later. The instruction to the DMD 106 is transmitted from the control unit 113 by indicating, for example, binary data indicating whether or not to irradiate laser light should be arranged in a two-dimensional array.

The half mirror 104, the mirror 105, and the mirror 105 so that the direction of the reflected light becomes the vertical direction when the incident light incident on the DMD 106 from the mirror 105 is reflected by the micromirror in the ON state. And a DMD 106 are disposed. The half mirror 109 and the objective lens 110 are provided on the optical path of the laser light reflected by the micromirror in the ON state and reaching the surface of the workpiece 102, An optical system is disposed. The laser light reflected by the micromirror in the ON state is projected or irradiated onto the surface of the work 102 through the projection optical system. The projection optical system is configured so that the surface of the workpiece 102 and the DMD 106 are in a conjugate position.

The off-state micromirrors are different from when the tilt angle is on. Therefore, the incident light incident on the DMD 106 from the mirror 105 is reflected in a direction different from the direction of reaching the half mirror 107 in the off-state micromirror, and is not irradiated onto the workpiece 102. In Fig. 1, the optical path of the reflected light by the micromirror in the off state is indicated by a dashed arrow.

Therefore, by controlling the individual micromirrors to be in an on state or an off state, it is possible to control whether laser light is irradiated to the position on the workpiece 102 corresponding to each micromirror. That is, by using the DMD 106, the laser beam can be irradiated onto the workpiece 102 in an arbitrary position, direction and shape.

The laser processing apparatus 100 includes an LED (Light Emitting Diode) light source 116. Light emitted from the LED light source 116 (hereinafter referred to as "LED light") is reflected by the half mirror 104 and enters the mirror 105.

The laser oscillator 103, the half mirror 104 and the LED light source 116 are disposed such that the optical axes of the laser light transmitted through the half mirror 104 and the LED light reflected by the half mirror 104 coincide with each other . Therefore, the optical path of the LED light after being reflected by the half mirror 104 is the same as the optical path of the laser light, and the LED light is also applied to the workpiece 102. [

In this embodiment, calibration is performed to adjust irradiation of laser light through the DMD 106, and LED light is used for calibration.

The laser processing apparatus 100 also includes an illumination light source 111 and a CCD (Charge Coupled Device) camera 112. The illumination light from the illumination light source 111 is reflected by the half mirror 109 and irradiated onto the surface of the workpiece 102 through the objective lens 110. [ Instead of the CCD camera 112, an imaging device such as a CMOS (Complementary Metal-Oxide Semiconductor) camera may be used.

The reflected light from the surface of the work 102 of the laser light, the LED light and the illumination light is reflected by the optical system having the objective lens 110, the half mirror 109, the image forming lens 108 and the half mirror 107 And is incident on the photoelectric conversion element of the CCD camera 112. Thus, the CCD camera 112 picks up the surface of the workpiece 102.

In this embodiment, laser light, LED light, and illumination light of a wavelength capable of capturing the reflected light by the CCD camera 112 are used. Therefore, when the CCD camera 112 picks up the workpiece 102 with the laser light or the LED light irradiated by using the DMD 106, the picked-up image includes the laser light irradiated on the workpiece 102 A pattern of LED light appears.

If the laser machining apparatus 100 does not include any unevenness or misalignment, the pattern shown in the image matches the position, direction (angle), and shape with the pattern designated to the DMD 106. [ However, in reality, two patterns may not coincide. This discrepancy is subject to correction.

The laser processing apparatus 100 further includes a control unit 113, an operation unit 114, and a monitor 115. [

The control unit 113 controls the entire laser machining apparatus 100. The operation unit 114 is realized by an input device such as a keyboard or a pointing device. The instruction input from the operation unit 114 is sent to the control unit 113. [

In addition, the monitor 115 displays an image, a character, or the like in accordance with an instruction from the control unit 113. [ The monitor 115 may display an image of the workpiece 102 picked up by, for example, the CCD camera 112 in near real time. Hereinafter, an image captured by the CCD camera 112 and read by the control unit 113 may be referred to as a "live image ".

The control unit 113 will be described later in detail with reference to FIG. 2, but it will be briefly described as follows

The input to the control unit 113 is an instruction from the operation unit 114 and image data from the CCD camera 112. [ The control unit 113 controls the stage 101, the laser oscillator 103, the DMD 106, the monitor 115, and the LED light source 116.

The control unit 113 may be a general-purpose computer or a dedicated control device. The function of the control unit 113 may be realized by hardware, software, firmware, or a combination thereof.

For example, a CPU (Central Process Unit), a nonvolatile memory such as ROM (Read Only Memory), a RAM (Random Access Memory) used as a working area, an external storage device And a control unit 113 may be realized by a computer such as a personal computer (PC) having a connection interface with an external device and connected to each other by a bus.

In this case, the stage 101, the laser oscillator 103, the DMD 106, the monitor 115, and the LED light source 116 are connected to this computer by respective connection interfaces. The CPU realizes the function of the control section 113 by loading a program stored in a hard disk device or a computer-readable portable storage medium into the RAM and executing the program.

Next, the laser processing apparatus 100 is a laser repair apparatus for repairing defects by irradiating defects on the surface of the substrate with laser light to the substrate 102. In the laser processing apparatus 100 of the first embodiment, An overview of the operation of the apparatus 100 will be described.

1, the laser processing apparatus 100 includes a microscope including an image-forming lens 108 and an objective lens 110. The image- Therefore, the CCD camera 112 can capture fine circuit patterns and fine defects on the workpiece 102 through a microscope. The captured live image is displayed on the monitor 115 almost in real time.

A region in which a defect exists on the surface of the work 102 is referred to as a "defect region ", and a region in the image displayed on the monitor 115 where a defect region is captured is referred to as a" defect display region ". The laser repair apparatus recovers the substrate by irradiating the defective area with laser light. For example, dust or unnecessary resist is a defect that can be repaired because it can be evaporated by irradiation with a laser beam, though it is a defect. For example, such defects are objects of repair by a laser repair apparatus.

In order to prevent damage to the normally formed circuit pattern due to irradiation of the laser light to the defect-free region, the region irradiated with the laser light must match with the defect region with good accuracy. Therefore, calibration and adjustment are required.

For example, the operator selects or designates the defect display area through the operation unit 114. [ The designated defect display area is a pattern indicating a defective area. By designating this pattern to the DMD 106 by the control unit 113, it becomes possible to perform the irradiation controlled with "the laser beam is irradiated to the defective area and the laser beam is not irradiated to the area other than the defective area". In other words, by indicating the ON state with respect to the micromirrors of the DMD 106 corresponding to the pixels included in the defect display area and instructing the other micromirrors to be in the OFF state, the laser light is irradiated to the defective area, And other regions are not irradiated with laser light.

If there is no unevenness or deviation in the laser machining apparatus 100, the micromirror of the DMD 106 corresponding to the pixels included in the defect display area is positioned at a position on the workpiece 102 corresponding to the micromirror, It must be turned on to irradiate the light. In addition, the micromirrors corresponding to the pixels not included in the defective area must be turned off so as not to irradiate the laser beam to the position on the workpiece 102 corresponding to the micromirror.

However, in reality, the laser processing apparatus 100 may have unevenness or deviation. So calibration is done. Then, the laser light is adjusted based on the calibration result and irradiated onto the workpiece 102 as a substrate. As a result, the laser beam is irradiated with a pattern that matches the defective area on the substrate with good precision. That is, the laser processing apparatus 100, which is a laser repairing apparatus, can repair a defect in the substrate while preventing a normal portion from being damaged by laser light.

Next, the control unit 113 will be described in detail.

2 is a functional block diagram showing the function of the control unit 113 in the first embodiment.

The control unit 113 includes a receiving unit 201 for receiving an image from the CCD camera 112, a calculating unit 202 for performing calibration, an adjusting unit 203 for adjusting irradiation of light based on the result of the calibration, A spatial modulation control unit 204 for controlling the DMD 106, a stage control unit 205 for controlling the stage 101, and a selection unit (not shown) for selecting one of the laser oscillator 103 and the LED light source 116 as a light source 206). The adjustment device according to the present invention is realized in the first embodiment by the blowing section 201, the calculation section 202 and the adjustment section 203. [

The accepting unit 201 inputs an image of the workpiece 102 from the CCD camera 112. [ For example, when the control unit 113 is implemented by a PC, the blowing unit 201 may be realized by an image capture board mounted on a PC.

Although the type of the image to be received by the accepting unit 201 differs depending on the embodiment, in any embodiment, the image that the accepting unit 201 necessarily accepts is different from that of the workpiece 102 It is a picture.

The calibration pattern is a kind of input pattern instructed to the DMD 106. In the following description, the "input pattern" is a pattern indicating an instruction to the DMD 106, and an area (area) for irradiating the light is referred to as an " on " . Depending on the purpose for calibration or for processing by laser light, the pattern specifically designated as the input pattern is different.

In accordance with a certain input pattern, a pattern corresponding to the input pattern is generated on the image of the workpiece 102 on which the light is irradiated. Hereinafter, a pattern formed on an image is referred to as an "output pattern ".

The output pattern is a binary value of "light is irradiated" or "light is not irradiated" Quot; on "and" off "in the input pattern correspond to the states" light irradiated "and" no light irradiated "in the output pattern, respectively.

Generally, however, the input pattern and the output pattern are different due to the non-uniformity, deviation, and the like existing in the laser processing apparatus 100. [ For example, the calibration pattern is a reference pattern used for calibration, but the output pattern is different from the reference pattern.

That is, with reference to the input pattern, the output pattern is shifted from the reference position, rotated from the reference angle, or the shape is enlarged or reduced or deformed.

Thus, the calculating unit 202 calculates a conversion parameter for converting the input pattern into the output pattern. In each of the following embodiments, calibration is to calculate conversion parameters. Concrete examples of conversion parameters differ depending on the embodiment, and details will be described later.

The calculation unit 202 outputs the conversion parameter calculated when the calibration pattern is used as the input pattern to the adjustment unit 203. [ The calculating unit 202 may read a predetermined calibration pattern stored in a storage device (not shown) and use it for calculation of the conversion parameter, or may generate a calibration pattern for each calibration.

The adjustment unit 203 adjusts the irradiation of the laser light according to the irradiation pattern specified from the outside of the control unit 113 based on the conversion parameter. In the first embodiment, the adjustment unit 203 adjusts the irradiation pattern given from the operation unit 114, although the object to be controlled for adjustment varies depending on the embodiment.

When the control unit 113 is implemented by a PC, the calculating unit 202 and the adjusting unit 203 may be realized by a CPU that loads and executes the program in the RAM. When the calibration pattern is previously stored in the storage device, the storage device may be a RAM or a hard disk device provided in the PC.

The spatial modulation control unit 204 receives an input pattern to be instructed to the DMD 106 and controls the individual micro mirrors of the DMD 106 to be turned on or off according to the input pattern. As a result, the light emitted from the laser oscillator 103 or the LED light source 116 is spatially modulated by the DMD 106 and irradiated onto the workpiece 102.

The spatial modulation control unit 204 receives the calibration pattern as an input pattern from the calculation unit 202 in the irradiation of the LED light for calibration. The spatial modulation control unit 204 receives the input pattern adjusted by the adjustment unit 203 from the adjustment unit 203 in the irradiation of laser light for machining.

The stage control unit 205 controls the stage 101 to change the relative positions of the respective components of the optical system shown in Fig. 1 and the stage 101. As shown in Fig. In another embodiment, the relative position may be changed by moving an optical system other than the stage 101. [

For example, when the laser processing apparatus 100 is a laser repair apparatus, the defect inspection apparatus notifies the laser processing apparatus 100 of the approximate position of the defect to be restored in advance. The stage control unit 205 controls the stage 101 to move so that the position on the workpiece 102 that is notified is within the irradiation range of the laser beam and within the imaging range of the CCD camera 112.

Thereafter, the CCD camera 112 picks up the workpiece 102, and the picked-up image is picked up by the picking up unit 201, and the monitor 115 displays this picked-up image. The pattern to be restored by irradiating the laser beam, that is, the defect display area, is instructed by the operator from the operation unit 114 based on, for example, an image displayed on the monitor 115. [ Further, the defect display area may be extracted by a well-known technique by comparison with an image obtained from a workpiece of a good article.

The selection unit 206 selects one of the laser oscillator 103 and the LED light source 116 as a light source and turns on the selected light source and turns off the light source that is not selected. More specifically, the selection unit 206 controls the laser oscillator 103 to be turned off and the LED light source 116 to be turned on at the time of calibration, and the laser oscillator 103 is turned on and the LED And controls the light source 116 to be turned off. There are also cases where the selection unit 206 performs control to turn off both light sources together.

In the case where the control unit 113 is implemented by a PC, both the spatial modulation control unit 204, the stage control unit 205, and the selection unit 206 include a CPU for loading and executing a program into the RAM, Lt; / RTI &gt; interface.

Next, with reference to Fig. 3, an object to be calibrated will be described.

3 is a diagram illustrating deformation of an irradiation pattern due to a shift or unevenness existing in the laser machining apparatus 100, that is, deformation from an input pattern to an output pattern.

For convenience of explanation, the coordinate axis in the horizontal direction of the image captured by the CCD camera 112 is referred to as x axis, and the coordinate axis in the vertical direction is referred to as the y axis. The size of the image is arbitrary, but in this embodiment, 640 pixels in the x direction and 480 pixels in the y direction are used. This size is also expressed as "640 x 480 pixels ". The position of each pixel in an image is indicated by a set (x, y) of x coordinate and y coordinate. The coordinates of the upper left vertex and the lower right vertex of the irradiation pattern 310 in FIG. 3 are (0, 0) and (639, 479), respectively.

The irradiation pattern 310 shown in Fig. 3 is a pattern that indicates to which part of the image the laser beam should be irradiated to the image picked up by the CCD camera 112. Fig. Therefore, the position in the irradiation pattern 310 can be represented by the set (x, y) of the x coordinate and the y coordinate, and the size of the irradiation pattern 310 can be represented by the same value as the image picked up by the CCD camera 112 × 480 pixels.

Here, when the irradiation of laser light is shown as white and the irradiation is not shown as black, the irradiation pattern 310 can be expressed as a monochrome binary image, as shown in Fig. In the example of Fig. 3, the irradiation pattern 310 is composed of a white cross shape in which a bold line parallel to the x-axis and a bold line parallel to the y-axis meet at the center of the image and a background black color, The laser beam should be irradiated onto the portion of the workpiece 102 corresponding to the workpiece 102. [

In this embodiment, the irradiation pattern 310 is instructed from the operation unit 114 as follows. First, under the illumination by the illumination light from the illumination light source 111, the CCD camera 112 picks up the workpiece 102 in a state in which neither the laser light nor the LED light is irradiated. Then, the take-in unit 201 of the control unit 113 receives the captured image and outputs it to the monitor 115. [

Thereafter, the operator looks at the image output to the monitor 115 and instructs the operating unit 114 to specify the range to which the laser beam should be irradiated. This instruction is given to the control section 113 in the form of data of the irradiation pattern 310 of 640 x 480 pixels size through the interface connecting the operation section 114 and the control section 113. [

In another embodiment, the data of the irradiation pattern 310 may be sent to the control unit 113 from another apparatus. For example, when the laser machining apparatus 100 is a laser repair apparatus such as an FPD substrate, the data of the irradiation pattern 310 may be sent from the defect inspection apparatus to the control section 113. Alternatively, the laser repair apparatus may include an image recognition section, and the image recognition section may recognize the shape of the defect by image recognition processing, generate data of the irradiation pattern 310 indicating the recognized shape, and output it to the control section 113 .

Regardless of which method is used, data of the irradiation pattern 310 is given to the control section 113. The control unit 113 then generates the DMD transfer data 320 for instructing the DMD 106 to turn on and off the individual micromirrors from the irradiation pattern 310. [ The DMD transmission data 320 is data representing an input pattern and is transmitted (that is, transmitted) to the DMD 106. [

In the DMD 106, the micromirrors are arranged in a two-dimensional array, and the position of the micromirror can be represented by a combination of the u coordinate and the v coordinate (u, v). In order to simplify the explanation, the coordinate (x, y) of the pixel in the image and the coordinates (u, v)

x = u, y = v

. This relationship is established merely by appropriately arranging the micromirrors and appropriately defining the origin of the uv coordinate system, so that the generality of the following description is not lost.

Here, similarly to the drawing of the irradiation pattern 310, the DMD transfer data 320 can also be expressed as a monochrome binary image value, in which the irradiation of the laser beam is shown as white and the non-irradiation is indicated as black. In other words, the DMD transfer data 320 (black) is generated as a black-and-white binary value image indicating a point at the position (u, v) by white indicating that the micromirror is turned on or black indicating that the micromirror is turned off. ) Can be expressed.

In this embodiment, it is assumed that 800 x 600 micromirrors are arranged in the DMD 106. That is, the number of micromirrors is larger than the number of pixels of the image captured by the CCD camera 112. Therefore, the image representing the DMD transfer data 320 becomes an image surrounded by black margins around the image representing the irradiation pattern 310. [ The reason why such a margin exists will be described later.

(White or black) at the position (x, y) of the image representing the irradiation pattern 310 and the image showing the DMD transfer data 320 at the position where u = x, v = y (u, v) are the same. If the position (u, v) is

u < 0 or 640? u or v < 0 or 480? v

, The color at the position (u, v) of the image indicating the DMD transfer data 320 is black.

In FIG. 3, the DMD transfer data 320 includes a white rectangle frame line. The frame line represents a range of 640 x 480 pixels corresponding to the irradiation pattern 310 for convenience of explanation. It does not mean that the micromirrors on the white frame line are turned on. In this embodiment, the width of the margin above the white frame line in the DMD transfer data 320 is equal to the width of the lower margin, and the width of the margin on the right side is equal to the width of the margin on the left. However, the width of the margin may be appropriately determined according to the embodiment.

The control unit 113 generates the DMD transfer data 320 from the data of the irradiation pattern 310 based on the relationship between the irradiation pattern 310 and the DMD transfer data 320 as described above. As described above, in order to generate the DMD transfer data 320, the control unit 113 simply adds a black margin around the irradiation pattern 310. [

The spatial modulation control unit 204 in the control unit 113 outputs the DMD transfer data 320 to the DMD 106 to give an instruction to turn on or off each of 800 × 600 micromirrors.

Here, the micromirror of the DMD 106 is turned on or off according to the given DMD transfer data 320 itself without adjusting according to the calibration, and laser light is emitted from the laser oscillator 103 I suppose.

In this case, generally, the pattern of the laser beam irradiated on the workpiece 102 is different from the desired irradiation pattern 310. This is because the optical system and / or the image pickup system of the laser processing apparatus 100 are misaligned or uneven.

For example, there may be a mirror or lens that is skewed, a mounting position of each component of the laser processing apparatus 100 is shifted, or a mounted component is rotated from the original angle due to a shift in mounting angle.

The live image 330 in FIG. 3 is an example of an image picked up by the CCD camera 112 when a pattern different from the desired irradiation pattern 310 is irradiated onto the workpiece 102 in this manner. Therefore, the position on the live image 330 can also be represented by the xy coordinate system, and the size of the live image 330 is 640 x 480 pixels.

In the live image 330 of Fig. 3, the portion where the laser beam is actually irradiated is shown as white, and the portion where the laser beam is not irradiated is shown as black. When the live image 330 is compared with the irradiation pattern 310, the white cross shape moves in the positive direction of the x axis and is rotated about 15 degrees in the counterclockwise direction. The transformation from the irradiation pattern 310 to the live image 330 actually includes not only such parallel movement (shift) and rotation but also unevenness of shape such as enlargement or reduction, that is, scale transformation or shear deformation It is possible.

Therefore, in order to prevent such deformation, it is necessary to calibrate the irradiation of the laser light based on the result of the calibration. In the present embodiment, the above-described deformation of the irradiation pattern caused by the shift or unevenness existing in the laser processing apparatus 100 is regarded as a result of a kind of conversion, and this conversion is mathematically modeled.

Next, a process of calibrating the parameters representing the mathematically modeled conversion by calibration and adjusting based on the acquired parameters will be described.

In FIG. 3, the DMD transfer data 320 is the same as the irradiation pattern 310 except for the margin. Therefore, the irradiation pattern 310 is actually an input pattern designated to the DMD 106. The live image 330 is an output pattern generated in the image when the laser beam is irradiated on the work 102 without any adjustment corresponding to the input pattern. Therefore, the transformation from the irradiation pattern 310 to the live image 330 can be regarded as a conversion from the input pattern to the output pattern.

In this embodiment, this transformation employs a mathematical model called an affine transformation indicated by the transformation matrix T. [ That is, each element of the transformation matrix T is a transformation parameter to be calculated in the calibration.

As described above, both the input pattern and the output pattern can be represented by the xy coordinate system, and since u = x, v = y at all times, there is no problem in calculation of the conversion parameter even if the uv coordinate system and the xy coordinate system are equal. That is, the mathematical model in this embodiment is such that the coordinate (x, y) in the irradiation pattern 310 that is the same as the coordinate (u, v) in the DMD transmission data 320 is the transformation matrix T (X ', y') in the live image 330, as shown in Fig.

This mathematical model can be expressed as the following equation.

[Formula 1]

Here, the transformation matrix T is defined by a 3x3 matrix of Equation (2).

[Formula 2]

Then, the conversion from the input pattern to the output pattern can be represented by the matrix operation of Equation (3).

[Formula 3]

Here, the elements d ₁ and d ₂ in the third column of the transformation matrix T represent the amount of parallel movement. And, from the transformation matrix T, elements a _1, b _1, a _2, b In the part made of a 2 × 2 matrix _2, a 2 × 2 matrix is nonsingular matrix from the definition of the affine transformation, rotation, enlargement, reduction And shear deformation. This can be understood from the following equations (4) to (12).

That is, any regular 2x2 matrix S can be decomposed as shown in Equation (4).

[Formula 4]

In general, a matrix X representing rotation is represented by Expression 5, a matrix Y representing enlargement or reduction is represented by Expression 6, and a matrix Z representing shear deformation is represented by Expression 7.

[Formula 5]

[Formula 6]

[Equation 7]

Here, when?,?, And? Are expressed by Equations 8, 9, and 10 and? Satisfies Equations 11 and 12, the matrix S satisfies Equation 13.

[Equation 8]

[Equation 9]

[Equation 10]

[Equation 11]

[Equation 12]

[Formula 13]

S = XYZ

In other words, by calculating the transformation matrix T, it becomes possible to perform correction taking into consideration translation, rotation, expansion, reduction, and shearing deformation. Next, a method of calculating the transformation matrix T will be described.

In general, when three points a, b, and c are mapped to points a ', b', and c 'by affine transformation, the transformation matrix T representing affine transformation is obtained by multiplying the coordinates of points a, b, ', b', c 'as follows.

First, in the xy coordinate system,

Let the coordinates of point a be (x _a , y _a ) ^T

Let the coordinates of point b be (x _b , y _b ) ^T

Let the coordinates of point c be (x _c , y _c ) ^T

Let the coordinates of point a 'be (x _a ', y _a ') ^T

Let the coordinates of point b 'be (x _b ', y _b ') ^T

Let the coordinates of point c 'be (x _c ', y _c ') ^T

As shown in FIG. Here, the superscript character "T" represents transposition. Then, using the coordinates of the points a, b, c and the points a ', b', c ', a matrix P represented by the following expression 14 and a matrix Q represented by the following expression 15 can be defined.

[Equation 14]

[Formula 15]

From the equation 3, the relationship between the three points a, b, and c and the three points a ', b', and c 'can be expressed by the following equation (16).

[Formula 16]

TP = Q

to be. When the positions of the three points a, b, and c are appropriately selected, the matrix P becomes a regular matrix, and the backward column P ^-1 exists. Thus, Equation 17 can be obtained by multiplying the inverse column P ^-1 by the right side of both sides.

[Formula 17]

T = QP ^-1

Therefore, the calculation unit 202 can calculate the transformation matrix T from the equation (17). That is, if three points a, b and c at appropriate positions are determined so that the matrix P becomes a regular matrix and the positions of the points a ', b' and c 'mapped by the transformation matrix T can be known from these three points, T can be calculated. In this embodiment, the LED light is irradiated in accordance with the calibration pattern to know the positions of the points a ', b' and c '.

4 is a diagram showing an example of a calibration pattern. FIG. 4 shows an example of three calibration patterns, but these are patterns in which three points a, b, and c determined to be positioned so that the matrix P becomes a regular matrix are distinguishable from each other.

The calibration pattern may be generated by the calculation unit 202 for each calibration amount, or may be generated in advance and stored in the storage device.

Since the calibration pattern is a kind of input pattern to the DMD 106, it can be represented as a black binary value image showing the white state indicating the ON state and an OFF state indicating the ON state. 3, since the uv coordinate system is considered to be the same as the xy coordinate system in this embodiment, the x-axis and the y-axis are shown in Fig.

In the calibration pattern 340, three circles having different diameters are arranged, and three points can be distinguished according to the difference in diameter. That is, the center of a circle having the smallest diameter is the point a, the center of the circle having the second smallest diameter is the point b, and the center of the circle having the largest diameter is the point c. Since the circles having different diameters are different in area from each other, they can be distinguished from each other easily by image processing.

In the calibration pattern 341, three points are distinguished according to the shape. That is, the center of the rectangle is point a, the center of the rhombus is point b, and the center of the triangle is point c.

In the calibration pattern 342, three points are distinguished by using a figure composed of two line segments. In the calibration pattern 342, one end point of a line segment parallel to the y-axis is point a and the other end point is point b. The end point of the line segment parallel to the x-axis that is not in contact with the line segment ab is the point c. Here, if the contact point between the line ab and the line segment parallel to the x-axis is a point w, the distance a between the points a and w and the distance bw between the points b and w are different from each other. Can be determined.

Of course, other calibration patterns than those illustrated in Fig. 4 are available. For example, even in the case of a pattern consisting only of triangles whose three sides are different from each other, since the three vertices can be distinguished from each other based on the length of three sides, they can be used as a calibration pattern. It is also possible to use a pattern expressing four or more points that can be distinguished from each other, and only a specific three points among them may be used for calibration. In short, when the transformation matrix T adopts a mathematical model indicating the affine transformation, the calibration pattern may be any shape of the pattern as long as it is possible to distinguish the three points from each other.

By the way, according to the calibration pattern, when the CCD camera 112 picks up the workpiece 102 to which the light is irradiated, an image including the output pattern modified by the transformation matrix T can be obtained as described above. In order to calculate the transformation matrix T, it is necessary to recognize the positions of the points a ', b' and c 'from this output pattern.

Here, the cause of deformation due to the transformation matrix T is a deviation or unevenness that is latent in the laser machining apparatus 100, so that the degree of deformation by the transformation matrix T is not extreme. Therefore, even if the calibration pattern is somewhat deformed, by using the calibration pattern in which the degree of "easy discrimination of three points a, b, c is high" so as to maintain the property that "three points are distinguishable" ', b', c 'can be distinguished from each other and recognized.

For example, in the example of the calibration pattern 340, if the diameters of the three circles are different, the three points a, b, and c can be distinguished. However, this easily distinguishable degree differs depending on the ratio of the diameters of the three circles.

If the values of the three diameters are approximate, the three circles may be mapped to three ellipses (or circles) which are almost indistinguishable by the transformation matrix T. However, if the values of the three diameters are much different from each other, the three circles are mapped to three ellipses (or circles) which are different in area from each other and easy to distinguish even in the output pattern modified by the transformation matrix T. Thus, the three points a ', b', c 'are distinguishable. That is, the center of each of the three ellipses (or circles) can be recognized as three points a ', b', and c '.

That is, in the example of the calibration pattern 340, as the diameters of the three circles are much different from each other, the degree of easiness of distinguishing the three points a, b, and c is high. Whether the three points a ', b', c 'in the output pattern are distinguishable depends on the embodiment, when the diameters of the three circles in the calibration pattern 340 are somewhat different. Therefore, a preliminary experiment may be performed to determine the diameter of the three circles.

In the calibration pattern 341, triangles and squares are easily distinguishable in the output pattern. For example, if the lengths of the two sides of the rectangle are greatly different, or if the areas of the rectangle and rhombus are different from each other, the property that "three points are distinguishable" is maintained in the output pattern. Therefore, the center of each of the three graphic forms in the output pattern can be recognized as three points a ', b', and C '.

As for the calibration pattern 342, the two distances aw and bw are greatly different from each other, so that the property that "three points are distinguishable" is maintained in the output pattern, and the three points a ', b', c ' Can be recognized.

Next, with reference to FIG. 5, a process of calculating the transformation matrix T using such a calibration pattern will be described.

5 is a flowchart showing the calculation step of the transformation matrix T as the transformation parameter in the first embodiment.

In step S101, the calculation unit 202 generates a calibration pattern as shown in Fig. 4, for example, and outputs the calibration pattern to the spatial modulation control unit 204. [ Alternatively, the calculating unit 202 may read the calibration pattern stored in advance in the storage device in step S101.

The calibration pattern is designated as an input pattern in the DMD 106 and can be represented as a binary value image. Therefore, in Fig. 5, step S101 is referred to as "DMD image creation ".

Next, in step S102, the calculating unit 202 obtains the coordinates of the three points a, b, and c from the data of the calibration pattern.

For example, in the case of the calibration pattern 340 of Fig. 4, the calculation unit 202 recognizes three circles of "white" from the calibration pattern by the image recognition process, That is, the center of gravity) is calculated and acquired. These three coordinates are the coordinates of points a, b, and c.

In step S103, the selection unit 206 selects the LED light source 116 as a light source. Further, in accordance with the calibration pattern, the spatial modulation control unit 204 controls the DMD 106 so as to switch the on state and the off state of the micromirror. Thus, the LED light emitted from the LED light source 116 is spatially modulated in accordance with the calibration pattern, and projected (i.e., irradiated) onto the surface of the workpiece 102 through the DMD 106.

Then, in step S104, the CCD camera 112 picks up the workpiece 102, and the take-in unit 201 receives (i.e., captures) the image data of the picked-up image from the CCD camera 112 . In this image, there is an output pattern corresponding to the calibration pattern.

In the next step S105, the calculating unit 202 obtains the coordinates of the three points a ', b' and c 'from the output pattern of the image received by the taking unit 201 as follows.

In this embodiment, the image received by the accepting unit 201 is a grayscale image. Of course, in another embodiment, the CCD camera 112 for picking up a color image may be used. In such a case, however, the calculating unit 202 calculates the coordinates of the three points a ', b' and c ' do.

The calculating unit 202 first converts the image received by the receiving unit 201 into a monochrome binary image. This binarization is performed based on, for example, a comparison between the luminance value and the threshold value of each pixel. In the converted monochrome binary image, the white area is the area irradiated with the LED light, and the black area is the area not irradiated with the LED light. The calculation unit 202 performs the following processing using the converted monochrome binary image.

For example, when the calibration pattern 340 of FIG. 4 is used, the calculating unit 202 recognizes the existence and position of a circle or an ellipse-like shape by image recognition processing. As a result, three shapes are recognized. In the example of the calibration pattern 340, the areas of the three circles correspond to points a, b, and c, respectively, in ascending order. Accordingly, the calculating unit 202 calculates the areas of the three recognized shapes, and makes the shapes correspond to the points a ', b', and c ', respectively, in the order of small area. Further, the calculating unit 202 calculates the coordinates of the center of each of the three recognized shapes, and acquires these three coordinates as the coordinates of the three points a ', b', and c '.

Similarly, when another calibration pattern is used, the calculating unit 202 acquires the coordinates of the three points a ', b', and c 'from the monochrome binary image representing the output pattern in step S105.

Subsequently, in step S106, the calculation unit 202 calculates the transformation matrix T according to the above-mentioned equation (17). Here, the matrix Q is defined by the equation 15 from the coordinates of the three points a ', b' and c 'obtained in the step S105, and the matrix P is calculated from the coordinates of the three points a, b and c obtained in the step S102 Is defined.

Further, as described with respect to the expression (16), in the present embodiment, the matrix P is a regular matrix, and therefore the calculation section 202 can calculate the backward row P ^-1 in the step S106. Various methods are known for calculating the inverse column, and any method can be employed.

The calculation unit 202 stores the data of the transformation matrix T thus created in a storage device such as a RAM or a hard disk not shown in Fig.

Finally, in step S107, the calculation unit 202 calculates an inverse transformation matrix T '(= T ^-1 ) that is a backward train from the transformation matrix T. The inverse transformation matrix T 'is an inverse transformation parameter indicating an inverse transformation of the transformation by the transformation matrix T as a transformation parameter. The calculation unit 202 also stores the data of the inverse transformation matrix T 'in the storage device.

Thus, the process of Fig. 5, that is, the calibration is terminated. After the end of the calibration, irradiation with the laser beam from the laser oscillator 103, which has been adjusted according to the inverse transformation matrix T ', is performed. And, since the inverse transformation matrix T 'is calculated from the transformation matrix T, it should be noted that the adjustment based on the inverse transformation matrix T' is an adjustment based indirectly on the transformation matrix T.

6 is a diagram for explaining an adjustment method in the first embodiment.

The irradiation pattern 310 of FIG. 6 and the data 320 for DMD transmission are shown in FIG. 6 is a diagram for explaining using the transformation matrix T as shown in Fig.

In the first embodiment, the calculation unit 202 of FIG. 2 outputs the transformation matrix T already calculated and stored in the storage device and the inverse transformation matrix T 'to the adjustment unit 203.

The adjustment unit 203 also receives the irradiation pattern 310 from the operation unit 114 and generates the DMD transfer data 320. [ The adjustment unit 203 further converts the DMD transmission data 320 by the inverse transformation matrix T 'to generate the DMD transmission data 321 and outputs the data to the spatial modulation control unit 204. [

The spatial modulation control unit 204 designates the DMD transfer data 321 as an input pattern to the DMD 106 and controls the DMD 106. [ That is, the adjustment unit 203 has a function of designating the DMD transfer data 321 as an input pattern to the DMD 106 through the spatial modulation control unit 204. [

In the example shown in Fig. 6, as in Fig. 3, the transformation matrix T represents a transformation in which the movement in the positive direction of the x-axis and the rotation in the counterclockwise direction of about 15 are combined. 6, the DMD transfer data 321 transformed by the inverse transformation matrix T 'rotates the pattern of the DMD transfer data 320 in the clockwise direction by about 15 degrees, and moves the pattern in the minus direction of the x axis to be.

Here, when the selector 206 of FIG. 2 selects the laser oscillator 103 as a light source, laser light is emitted from the laser oscillator 103. This laser light is irradiated onto the workpiece 102 through the DMD 106 specified as the input pattern by the DMD transfer data 321. In the present embodiment, the CCD camera 112 images the workpiece 102, and the adjustment unit 203 receives an image from the CCD camera 112. [ The image thus received is the live image 331 in Fig.

6, the output pattern shown in the live image 331 is the same pattern as the irradiation pattern 310 because the deformation caused by the inverse transformation matrix T 'and the deformation caused by the transformation matrix T cancel each other out. The fact that the output pattern on the live image 331 and the irradiation pattern 310 are the same is precisely the same when the error due to the difference between the mathematical model expressed by Equation 3 and the actual transformation is ignored It means. In the following description, the term "is the same" is used in this sense unless otherwise stated.

The fact that the output pattern on the live image 331 is the same as the irradiation pattern 310 means that the adjustment is performed by the adjustment section 203 so that the laser beam is accurately irradiated to the position to be machined in the shape to be machined, It means that the image is captured as the live image 331.

As can be seen by comparing the DMD transmission data 320 and 321, as a result of the conversion by the inverse transformation matrix T ', the white portion indicating that the micromirror should be turned on is the DMD transmission data 321 )

u < 0 or 640? u or v < 0 or 480? v

May be exceeded. Therefore, in the present embodiment, the DMD 106 having more (for example, 800x600) micromirrors than the number of pixels (for example, 640x480 pixels) of the image representing the irradiation pattern 310 Is used. In this case, as shown in FIG. 3 or 6, the image representing the DMD transmission data 320, which is the input pattern designated to the DMD 106, , Indicating that the light is not irradiated).

Here, the transformation matrix T represents the influence of non-uniformity or deviation existing in the laser processing apparatus 100. Such unevenness or deviation falls within a range allowed by the specification of the laser processing apparatus 100. [ Therefore, the degree of transformation by the transformation matrix T is not extremely large. That is, an extremely large margin is not necessary. For example, the number of micromirrors required for the DMD 106 may be determined based on the amount of margin required experimentally and the amount of the estimated margin.

Next, the second embodiment and the third embodiment will be described with reference to Figs. 7 to 11. Fig. In the second embodiment and the third embodiment, the adjustment method of adjusting the irradiation of the laser light, that is, the operation of the adjustment unit 203 after obtaining the conversion parameters, is different from that of the first embodiment. There are various adjustment methods for canceling the conversion indicated by the conversion parameter, and therefore, it is preferable to employ an appropriate adjustment method according to the embodiment.

7 is a diagram for explaining an example of conversion from an input pattern to an output pattern as a premise for explaining the adjustment method in the second embodiment and the third embodiment. The contents of FIG. 7 are similar to those of FIG. 3, but the method shown in FIG. 3 differs from that of FIG. 7 for convenience of explanation.

In the second and third embodiments, as shown in Figs. 8 and 10, the configuration of the control section 113 is partially different from the configuration of Fig. 2 in the first embodiment, , There is no influence due to the difference from Fig.

7 is an image captured by the CCD camera 112 in a state where only the illumination light from the illumination light source 111 is irradiated onto the workpiece 102 mounted on the stage 101. [ In the example of Fig. 7, there are three linear circuit patterns on the workpiece 102. Fig.

When the image 300 is received by the take-in unit 201 and output to the monitor 115, the operator designates the machining object range through the operation unit 114. [ The specified range is a range of rectangles painted with the image 300 points.

The spatial modulation control unit 204 receives a designation from the operation unit 114 and generates an irradiation pattern 311 based on this designation. In the image representing the irradiation pattern 311, the range of the rectangle specified on the image 300 is white, and the other is a black image. The input pattern designated to the DMD 106 in correspondence to the irradiation pattern 311 can be represented by an image surrounded by only the black margin around the irradiation pattern 311 although not shown. The spatial modulation control unit 204 also generates an input pattern to the DMD 106 corresponding to the irradiation pattern 311. [

Modulated by the DMD 106 is irradiated onto the workpiece 102 in accordance with the instruction of the input pattern corresponding to the irradiation pattern 311 and the workpiece 102 is irradiated by the CCD camera 112 Upon image capture, a live image 332 can be obtained. In the example of Fig. 7, the range in which the laser beam is actually irradiated in the live image 332 is a range of rectangles painted with dots and is different from the range to be machined specified for the image 300. [

When the image 300 and the live image 332 are compared, the position, direction, and shape of the circuit pattern are the same. However, it can be seen that laser light is irradiated in a pattern different from the input pattern given in the image 300 and given to the DMD 106. [ The transformation of the output pattern from this input pattern is indicated by the transformation matrix T. 3 and Fig. 7, the concrete values of the individual elements of the transformation matrix T are different in Fig. 3 and Fig. 7 shows a case in which the transformation matrix T represents a rotation of about 30 degrees counterclockwise around the center of the live image 332 for the sake of simplicity.

The second embodiment will be described below with reference to Figs. 8 and 9 on the assumption that it has been described with reference to Fig.

8 is a functional block diagram showing the function of the control unit 113 in the second embodiment. 2, which shows the first embodiment, the control unit 113 includes a receiving unit 201, a calculating unit 202, an adjusting unit 203, a spatial modulation controlling unit 204, a stage controlling unit 205, 206 is similar to that shown in Fig.

The difference from FIG. 2 in FIG. 8 is the flow of data and / or control indicated by arrows. That is, since the first embodiment and the second embodiment are different in the adjustment method, an arrow pointing to the adjustment section 203 and an arrow pointing out from the adjustment section 203 are different in FIG. 2 and FIG. The meaning of the arrows in Fig. 8 becomes clear from the adjustment method described below with reference to Fig.

9 is a view for explaining an adjustment method in the second embodiment.

The relative position between the optical system of the laser processing apparatus 100 and the stage 101 is changed by controlling the movement of the stage 101 by the stage control unit 205 shown in Fig. The kind of movement of the controllable stage 101 may be different according to the embodiment, but in the second embodiment, the stage control unit 205 controls the motion of the stage 101 of the following kind.

(a) Vertical movement

(b) translation in a plane horizontal to the vertical axis

(c) Rotation in a plane horizontal to the vertical axis

(d) a movement of changing the angle between the upper surface of the stage 101 and the vertical axis

That is, in the second embodiment, a driving motor and / or an actuator (not shown) for enabling these types of motions are mounted on the stage 101. [ The stage control unit 205 controls the driving motor and / or the actuator to move the stage 101.

In the second embodiment, the workpiece 102 is fixed on the stage 101 by a stopper or the like if necessary. Even if the stage 101 is tilted by the movement of the above (d) The workpiece 102 slips and does not fall.

In this configuration, the calculating unit 202 outputs to the adjusting unit 203 the data of the transform matrix T already calculated and stored in the storage device. Then, the adjustment unit 203 instructs the stage control unit 205 to control the stage 101 to move based on the transformation matrix T. The stage control unit 205 causes the stage 101 to move in accordance with an instruction from the adjustment unit 203. [ As a result of this control, the relative position between the optical system of the laser machining apparatus 100 and the workpiece 102 also changes in accordance with the transformation matrix T. [

At this point, for convenience of explanation, it is assumed that the CCD camera 112 picks up the workpiece 102. Then, as shown in Fig. 9, an image 301 equivalent to an image in which the image 300 is transformed by the transformation matrix T is captured. In Fig. 9, by the comparison of the circuit patterns on the workpiece 102 picked up on the images 300 and 301 respectively, deformation by the transformation matrix T can be visually confirmed.

On the other hand, the irradiation pattern 311 is specified based on the image 300 as described in Fig. Then, based on the designated irradiation pattern 311, the spatial modulation control section 204 assigns the input pattern to the DMD 106. [ Then, the selection unit 206 selects the laser oscillator 103 as a light source.

Then, the laser light emitted from the laser oscillator 103 is irradiated onto the workpiece 102 under the influence of the shift or unevenness indicated by the transformation matrix T. However, unlike the case of Fig. 7, the second embodiment is a state after the movement corresponding to the workpiece 102 itself or the transformation matrix T is performed at the time when the laser beam is irradiated, as shown in the image 301 . Since the irradiated laser beam and the workpiece 102 are both affected by the same transformation matrix T, the influence of the transformation matrix T is canceled. That is, as a result of the adjustment, the laser light is irradiated accurately on the designated area.

This is illustrated in FIG. 9 as follows. In the live image 333 in which the CCD camera 112 picks up the workpiece 102 in the state that the laser light is irradiated, a range in which the laser light is actually irradiated is shown by being dotted. When the image 300 and the live image 333 are compared with each other, the direction of the line of the three circuit patterns and the part of the image printed on the image are different, but the relative relationship between the lines of the three circuit patterns and the area painted with the network is the same. That is, the laser beam is irradiated accurately to the desired region.

As apparent from the above description, in the second embodiment, the processing in step S107 in Fig. 5 can be omitted.

The value of the control parameter necessary for moving the stage 101 according to the transformation matrix T may be determined experimentally or may be calculated by the specification of the laser processing apparatus 100 or the like.

For example, the movement of (a) may be performed by moving the stage 101 upward or downward by 1 mm along the vertical axis, the magnification ratio of the image picked up by the CCD camera 112 or the value of the reduction ratio May be examined experimentally in advance. The adjustment unit 203 calculates the amount of movement in the vertical direction on the basis of the magnification or reduction factor included in the transformation matrix T based on the value examined in advance and outputs the calculated amount of movement as the control parameter of the stage 101 to the stage control unit 205 . Similarly, the adjustment unit 203 can acquire the values of the control parameters for the motions (b) to (d).

It is apparent from the above description that the adjusting method of the second embodiment is suitable for a case where the mechanism for moving the stage 101 has high mechanical precision.

Next, referring to Figs. 10 and 11, the adjustment method in the third embodiment will be described. In the third embodiment, the adjustment unit 203 performs adjustment by image processing.

10 is a functional block diagram showing the function of the control section 113 in the third embodiment. 2, which shows the first embodiment, the control unit 113 includes a receiving unit 201, a calculating unit 202, an adjusting unit 203, a spatial modulation controlling unit 204, a stage controlling unit 205, 206 is similar to that shown in Fig.

The difference from Fig. 10 and Fig. 2 is the flow of data and / or control indicated by arrows. That is, since the first embodiment and the third embodiment are different in the adjustment method, the arrows pointing to the adjustment section 203 and the arrows departing from the adjustment section 203 are different in FIG. 2 and FIG.

2 shows an arrow from the intake unit 201 to the monitor 115 indicating the output of the image read from the CCD camera 112 to the monitor 115 in order to designate the irradiation pattern, There is no. As described below, in the third embodiment, adjustment is performed from the designation step of the irradiation pattern. The meaning of the other arrows will also become apparent from the adjustment method described below with reference to Fig.

11 is a view for explaining an adjustment method in the third embodiment.

11, the image 302 is an image captured by the CCD camera 112 and received by the capturing unit 201 from the CCD camera 112. Lines of three circuit patterns similar to those of the image 300 of Fig. 7 or Fig. 10 are also printed on the image 302. Fig.

In the adjustment in the third embodiment, first, the calculation unit 202 outputs to the adjustment unit 203 the data of the inverse transformation matrix T 'already calculated and stored in the storage device. The adjustment unit 203 performs image processing for modifying the image 302 by the inverse transformation matrix T 'to generate the image 303 and outputs the image 303 to the monitor 115. [

In Fig. 11, as shown in Fig. 7, the transformation matrix T represents a rotation of about 30 degrees counterclockwise. Therefore, in the image 303, the lines of the three circuit patterns are inclined by about 30 DEG in the clockwise direction as compared with the image 302. [

The operator looks at the image 303 displayed on the monitor 115 and designates an area to be irradiated with laser light through the operation unit 114. [ In the image 304 of Fig. 11, the designated area is indicated by being dotted. The spatial modulation control unit 204 receives a designation from the operation unit 114 and generates an irradiation pattern 312 based on this designation. The irradiation pattern 312 corresponds to the area of the image 304 painted with dots.

The spatial modulation control unit 204 also generates an input pattern to be designated to the DMD 106 based on the irradiation pattern 312. [ Then, the spatial modulation control section 204 designates the input pattern to the DMD1 06. Further, the selection unit 206 selects the laser oscillator 103 as a light source.

Then, the laser light emitted from the laser oscillator 103 is irradiated onto the workpiece 102 under the influence of the shift or unevenness indicated by the transformation matrix T. However, when laser light is irradiated on the basis of the irradiation pattern 312 designated on the basis of the image 304 transformed by the inverse transformation matrix T 'and this irradiation is influenced by the transformation matrix T, the inverse transformation matrix T' The influence and the influence of the transformation matrix T are canceled. That is, as a result of the adjustment, the laser light is irradiated accurately to the designated desired area.

This is illustrated in FIG. 11 as follows. In the live image 334 in which the CCD camera 112 picks up the workpiece 102 in the state that the laser light is irradiated, a range in which the laser light is actually irradiated is shown by being dotted. When the image 304 and the live image 334 are compared with each other, the direction of the lines of the three circuit patterns and the portions printed on the image are different, but the relative relationship of the lines drawn by the three circuit patterns and the regions drawn by the dots is the same. That is, laser light is irradiated accurately to a designated desired area.

Although the transformation matrix T has been described as an example in which the transformation matrix T represents a relatively simple variant with respect to the second and third embodiments, the transformation by the transformation matrix T is not limited to parallel movement, rotation, Or a complex variant involving all of the reduction.

Next, the fourth to sixth embodiments will be described. The fourth to sixth embodiments are different from the first embodiment in that the mathematical model of the conversion from the input pattern to the output pattern is different from that of the first embodiment and the operation of the control section 113 is different according to the difference of the mathematical model, This is the same as the embodiment. Which mathematical model is desired to be adopted depends on the characteristics and the degree of the unevenness or deviation in the actual laser processing apparatus 100. [

In the fourth embodiment, a mathematical model considering only parallel movement (shift) and rotation is employed. The calibration pattern of the fourth embodiment is only required to be able to indicate two points a and b which are distinguishable from each other. For example, in the fourth embodiment, a pattern composed of two circles having diameters different from each other can be used in place of the calibration pattern 340 in Fig.

Similar to the first embodiment,

Let the coordinates of point a be (x _a , y _a ) ^T

Let the coordinates of point b be (x _b , y _b ) ^T

Let the coordinates of point a 'be (x _a ', y _a ') ^T

Let the coordinates of point b 'be (x _b ', y _b ') ^T

As shown in FIG. In the fourth embodiment, the calculating unit 202 calculates, from these four coordinates,

The amount of translation in the x direction:

[Formula 18]

d ₁ = x _a '- x _a

The amount of translation in the y direction:

[Formula 19]

d ₂ = y _a '- y _a

Amount of rotation:

[Formula 20]

_{^{θ = tan -1 {(y b}} '- y a') / (x b '- x a')} - tan -1 {(y b - y a) / (x b - x a)}

The conversion parameters are calculated. These conversion parameters may be expressed in the form of a transformation matrix T of Equation 2 as in the first embodiment. In other words,

[Formula 21]

a ₁ = cos?

[Formula 22]

b ₁ = -sin?

[Equation 23]

a ₂ = sin?

[Equation 24]

b ₂ = cos?

And Equation (2). The operation of the laser machining apparatus 100 after the calculation unit 202 calculates the transformation matrix T in this way is the same as that in the first embodiment.

In the fifth embodiment, a mathematical model considering only parallel movement (shift) is employed. The calibration pattern of the fifth embodiment is only required to be able to represent only one point a. For example, in the fifth embodiment, a pattern consisting of only one circle can be used in place of the calibration pattern 340 in FIG.

Similar to the first embodiment,

Let the coordinates of point a be (x _a , y _a ) ^T

Let the coordinates of point a 'be (x _a ', y _a ') ^T

As shown in FIG. In the fifth embodiment, the calculating unit 202 calculates the amount of parallel movement d ₁ in the x direction and the parallel movement in the y direction from Equations 18 and 19, as in the fourth embodiment, from these two coordinates And calculates two conversion parameters of the amount d ₂ . These conversion parameters may be expressed in the form of a transformation matrix T of Equation 2 as in the first embodiment. In other words,

[Formula 25]

a ₁ = 1

[Equation 26]

b ₁ = 0

[Equation 27]

a ₂ = 0

[Equation 28]

b ₂ = 1

And Equation (2). The operation of the laser machining apparatus 100 after the calculation unit 202 calculates the transformation matrix T in this way is the same as that in the first embodiment.

In the sixth embodiment, pseudo-affine transformation is adopted as a mathematical model. In the pseudo-affine transformation, trapezoidal deformation is considered in addition to parallelogram deformation (shear deformation) considered in the affine transformation. In the sixth embodiment, a calibration pattern indicating four points a, b, c, and d distinguishable from each other is used. For example, in the sixth embodiment, a pattern composed of four circles having diameters different from each other can be used in place of the calibration pattern 340 shown in Fig.

Similar to the first embodiment,

Let the coordinates of point a be (x _a , y _a ) ^T

Let the coordinates of point b be (x _b , y _b ) ^T

Let the coordinates of point c be (x _c , y _c ) ^T

Let the coordinates of point a 'be (x _a ', y _a ') ^T

Let the coordinates of point b 'be (x _b ', y _b ') ^T

Let the coordinates of point c 'be (x _c ', y _c ') ^T

As shown in FIG. Also, similarly,

Let the coordinates of the point d be (x _d , y _d ) ^T

Let the coordinates of the point d 'be (x _d ', y _d ') ^T

As shown in FIG.

The pseudo-affine transformation is modeled by Eq. (29).

[Equation 29]

The transformation matrix T is defined as Equation 30.

[Formula 30]

Similarly to the first embodiment, by using the coordinates of the points a, b, c and d and the coordinates of the points a ', b', c 'and d', the matrices P and Q can be defined .

[Formula 31]

[Formula 32]

From Equation 29, the relationship between the four points a, b, c, and d and the four points a ', b', c ', and d'

[Equation 33]

TP = Q

If the positions of the four points a, b, c, and d are appropriately selected, the matrix P becomes a regular matrix, and since the inverse matrix P ^-1 exists, Expression 34 can be obtained from Expression 33.

[Equation 34]

T = QP ^-1

Therefore, the calculation unit 202 can calculate the transformation matrix T from the equation (34). Further, the calculating unit 202 may calculate an inverse transformation matrix T 'from the transformation matrix T. [

As described in the first to sixth embodiments, the mathematical model of the conversion from the input pattern to the output pattern varies. According to the above description, an example in which the minimum number of points required by the calibration pattern is calculated in order to calculate the conversion parameters in the adopted mathematical model has been described.

However, a calibration pattern indicating more points may be used. For example, similarly to the first to third embodiments, when affine transformation is applied as a mathematical model, a calibration pattern showing m points that can be distinguished from each other by m? 4 may be used. In this case, for each i that satisfies 1? I? M, the elements a _l , b _l , d _l , a ₂ , b ₂ , the calculation unit 202 may calculate the value of d ₂ .

[Formula 35]

(x _i ', y _i ', 1) ^T = T (x _i , y _i , 1) ^T

And wherein (x _i, y _i) ^T is a column that indicates the coordinate of the i-th point of the representation of the calibration pattern vector, (x _i ', y _i') ^T is the coordinate of the output pattern of the dots of the i-th Lt; / RTI &gt;

Next, the seventh embodiment will be described with reference to Figs. 12 and 13. Fig. According to the seventh embodiment, even if the surface of the workpiece 102 has irregularities, the accuracy of the calibration does not deteriorate.

Generally, if there is a three-dimensional three-dimensional shape on the surface of the workpiece 102, that is, irregularities, the accuracy of the calibration may be lowered. This is because the shape of the output pattern corresponding to the calibration pattern may be skewed due to the influence of the unevenness and the reflectance of the surface material.

For example, when the calibration pattern 340 of FIG. 4 is used, the outline of the circle that represents the point a may traverse the uneven portion on the workpiece 102 by chance. At this time, the shape representing the point a in the output pattern is skewed.

Therefore, the coordinate calculated by the calculating unit 202 as the position of the point a 'corresponding to the point a is the center coordinate of the non-uniform shape, and includes an error definitely. For example, the amount of error may be several pixels. In this case, since the conversion matrix T is calculated based on the coordinates including the error, the accuracy of the calibration is lowered. As a result, it is difficult to adjust with high accuracy.

For example, when the workpiece 102 is an FPD substrate or a laminated printed substrate, a circuit pattern of a three-dimensional shape is formed on the workpiece 102. [ The circuit pattern can be an obstacle to distort the shape when the calibration pattern is irradiated. Therefore, depending on the position at which the calibration pattern is irradiated, the accuracy of calibration may be lowered.

In order to prevent this problem and perform calibration with good accuracy, a substrate on which no circuit pattern is formed or a margin area on the outer periphery of the substrate on which no circuit pattern is formed may be used for calibration. However, the detail will be described later, but it may be required to perform the calibration by using the region of the workpiece 102 which is actually to be processed. According to the seventh embodiment, even in such a case, deterioration in the accuracy of calibration can be prevented.

12 is an example of an image that is captured when a calibration pattern is irradiated in the seventh embodiment. The image 306 in Fig. 12 is an image captured by the CCD camera 112 when a calibration pattern is irradiated on the substrate 401 which is the workpiece 102. Fig. A circuit pattern 402 in a three-dimensional state formed on the substrate 401 and circles 403, 404, and 405 constituting an output pattern corresponding to the calibration pattern are printed on the image 306. [ In the image 306, since all the circles 403, 404, and 405 are not overlapped with the circuit pattern 402, the shape is not much skewed.

In the substrate 401, a portion on which the circuit pattern 402 is not formed is a background portion. In the substrate 401, a flat portion with relatively small unevenness is referred to as a "background portion". By controlling the control section 113 so as to irradiate the calibration pattern on the background portion, it is possible to prevent the lowering of the calibration accuracy even if the surface of the workpiece 102 has irregularities.

13 is a functional block diagram for explaining the function of the control section 113 in the seventh embodiment. Fig. 13 differs from Fig. 2 in that a creation unit 207 is added. The creating unit 207 creates a calibration pattern so that light is irradiated to the background portion of the workpiece 102 due to unevenness. Therefore, in the seventh embodiment, the preliminary calibration and the preliminary adjustment are performed. Hereinafter, the pattern designated as the input pattern in the preliminary calibration is referred to as "preliminary calibration pattern ".

Hereinafter, the operation of the laser machining apparatus 100 in the seventh embodiment will be described in comparison with the first embodiment.

First, the creating unit 207 selects the appropriate three points a to c, and prepares a preliminary calibration pattern having a shape that allows the points a to c to be distinguished from each other. Here, the coordinates of the points a to c are denoted by

(x _a , y _a ) ^T and (x _b , y _b ) ^T and (x _c , y _c ) ^T

As shown in FIG. Then, a preliminary calibration using this preliminary calibration pattern is performed.

That is, the selecting unit 206 selects the LED light source 116 as the light source, the creating unit 207 outputs the preliminary calibration pattern to the spatial modulation control unit 204, and the spatial modulation control unit 204 sets the preliminary calibration pattern And is designated to the DMD 106 as an input pattern. Thus, the LED light is irradiated according to the preliminary calibration pattern.

Then, the CCD camera 112 picks up the workpiece 102 to which the LED light is irradiated, and the take-in unit 201 receives the image.

The calculating unit 202 calculates the coordinates of the points a ', b', and c 'corresponding to the points a, b, and c on the output pattern generated on the image corresponding to the preliminary calibration pattern. Respectively,

(x _a ', y _a ) ^T and (x _b ', y _b ) ^T and (x _c ', y _c ) ^T

As shown in FIG. The coordinates of the three points a, b, and c defining the preliminary calibration pattern are output from the creating unit 207 to the calculating unit 202.

Here, by the same method as that of the conversion matrix T calculated in the first embodiment, the calculating unit 202 calculates,

(x _a , y _a ) ^T and (x _b , y _b ) ^T and (x _c , y _c ) ^T and

(x _a ', y _a ) ^T and (x _b ', y _b ) ^T and (x _c ', y _c ) ^T

The transformation matrix T ₁ is calculated. The calculation unit 202 outputs the transformation matrix T ₁ to the creation unit 207.

Write unit 207 calculates a conversion inverse transformation matrix T ₁ '= T ₁ ^-1 of the matrix T _1. Alternatively, the calculating unit 202 may calculate the inverse transformation matrix T ₁ 'and output it to the creating unit 207.

The above process is a preliminary calibration. In the preliminary calibration, as described above, errors that can not be neglected by the influence of the concavity and convexity on the workpiece 102 are calculated by the coordinates of the calculated points a ', b', c ', the transformation matrix T ₁ , The inverse transform matrix T ₁ 'may be included. However, since the transformation matrix T ₁ is not much different from the transformation matrix to be finally obtained, it is sufficiently effective to be used for the preliminary adjustment.

Next, the CCD camera 112 picks up the workpiece 102 which is only illuminated by the illumination light source 111 and in which the laser light or the LED light is not irradiated. The accepting unit 201 receives an image (hereinafter referred to as "background detecting image"), and the creating unit 207 performs the background detecting process using the background detecting image.

The background detection processing is processing for detecting a region (hereinafter referred to as "background region") on the background of the workpiece 102 in the background detection image.

For example, the creating unit 207 applies an image shading filter for background detection, removes an image of projections and depressions (for example, a circuit pattern) on the workpiece 102, which is photographed on the background detection image, . Then, the creating unit 207 calculates the difference between the pixel value in the background detection image and the pixel value in the background image for each pixel.

In the background region, the absolute value of the difference is small, and the absolute value of the difference is large in the region where the projections and depressions on the workpiece 102 are imprinted (hereinafter referred to as "non background region"). Thus, the creating unit 207 detects, for example, an area having a smaller absolute value of the difference than a predetermined threshold as a background area.

In order to detect the background area, various image processing methods such as edge extraction and feature point extraction can be used in addition to the method of using the shading filter as described above.

Further, the creating unit 207 selects the appropriate three points d ₁ , e ₁ , and f ₁ belonging to the detected background area. Let the coordinates of the three points d ₁ , e ₁ , and f _{1 be}

(x _d1 , y _d1 ) ^T , (x _e1 , y _e1 ) ^T and (x _f1 , y _f1 ) ^T

As shown in FIG.

Here, it is preferable to select, as the three points d ₁ , e ₁ , and f ₁ , a point located far from the background area in the background area. This is because it is easy to form a calibration pattern in which light is not irradiated on the concavities and convexities on the workpiece 102.

Next, the creating unit 207 transforms the coordinates of the three points d ₁ , e ₁ , and f ₁ using the inverse transformation matrix T ₁ ', respectively. The three points indicated by the converted coordinates are denoted by d, e, and f. In the first embodiment, from the comparison with the processing in which the adjustment unit 203 obtains the DMD transmission data 321 by converting the DMD transmission data 320 of FIG. 6 into the inverse transformation matrix T ', the inverse transformation matrix T ₁ ' It is possible to understand that the process of obtaining the coordinates of d, e, and f for three points is a preliminary adjustment.

The creating unit 207 creates a calibration pattern capable of distinguishing the three points d, e, and f based on the coordinates of the three points d, e, and f obtained by the preliminary adjustment and outputs the calibration pattern to the calculating unit 202 do. Let the coordinates of the three points d, e, and f be

(x _d , y _d ) ^T and (x _e , y _e ) ^T and (x _f , y _f ) ^T

As shown in FIG. The calibration pattern is a pattern representing these three coordinates.

The calibration pattern in the seventh embodiment is set based on the detected background area so that the range where the light is actually irradiated is included in the background part as much as possible, that is, the light is not irradiated as much as possible outside the background part.

For example, when three points d, e, and f are indicated by three circles having diameters different from each other as in the calibration pattern 340 in FIG. 4, if an unnecessarily large diameter circle is used, Light may be irradiated in a three-dimensional shape.

In other words, in the image of the workpiece 102 in that state, the range in which the light is actually irradiated may overlap the non-background area. Therefore, when a calibration pattern composed of three circles having different diameters is employed, it is preferable that the preparation section 207 defines the diameter of the three circles according to the shape and position of the background region.

Likewise, when the calibration pattern 341 or 342 of FIG. 4 or another type of calibration pattern is adopted, the preparation section 207 similarly generates a calibration pattern so that the range in which the light is actually irradiated is included in the background section as much as possible Create.

For example, the creating unit 207 may create a provisional pattern indicating the three points d1, e1, and f1, and create a calibration pattern based on the provisional pattern.

For example, the creating unit 207 creates a provisional pattern so that all the portions indicating the irradiation of light are included in the background area. In addition, the provisional pattern is formed and determined by the creating unit 207 so that the distance from the non-background area of the portion indicating the irradiation of light is not less than the threshold value as much as possible.

As described above, the transformation matrix T ₁ or the inverse transformation matrix T ₁ 'may include errors, but it is not much different from the transformation matrix to be finally obtained. Therefore, if the value of the threshold value is appropriate, when a pattern obtained by converting the provisional pattern into the inverse transformation matrix T ₁ 'is used as the input pattern, it is expected that light is actually irradiated only to the background portion. Therefore, it is appropriate to use a pattern obtained by converting a provisional pattern into an inverse transformation matrix T ₁ 'as a calibration pattern. An appropriate threshold value can be obtained, for example, by an experiment.

Also, the shape in the provisional pattern may not be maintained in the calibration pattern. In this case, for example, if the point d1 is represented by the center of the circle, the point d in the calibration pattern is represented by the shape other than the circle, and it may be difficult to calculate the coordinates of the point d from the output pattern. However, for example, if the point d1 is represented by the midpoint of one short line segment, the point e1 is represented by the intersection of two short line segments, and the point f1 is represented by the intersection of the three short line segments, There is no problem even if the shape of the pattern is not maintained in the calibration pattern.

Anyway, the creating unit 207 uses the inverse transformation matrix T ₁ 'so that light is irradiated only to the background portion as much as possible. Based on the three points d 1, e 1, and f ₁ belonging to the background region, Create a calibration pattern defined by f. The process after the calibration pattern is created, that is, calibration and adjustment, is the same as in the first embodiment.

That is, the selection unit 206 selects the LED light source 116 as the light source, and the spatial modulation control unit 204 controls the DMD 106 based on the calibration pattern so that the LED light is emitted to the workpiece 102). Then, the CCD camera 112 picks up the workpiece 102 to which the LED light is irradiated, and the take-in unit 201 receives the image.

When the calibration pattern created as described above is examined, for example, as shown in Fig. 12, in the accepted image, the portion irradiated with light is expected to be included in the background area. That is, the calibration pattern prepared as described above is expected to prevent a reduction in the accuracy of calibration.

The calculation unit 202 calculates the coordinates of the three points d ', e', and f 'corresponding to the points d, e, and f from the output pattern generated in accordance with the calibration pattern on the received image

(x _d ', _d y') ^T and _{(x e ', y e'} ) T and (x _f ', _f y') ^T

. The calculation unit 202 calculates the transformation matrix T ₂ and its inverse transformation matrix T ₂ from the coordinates of the points d, e and f and the coordinates of the points d ', e' and f ' T ₂ '= T ₂ ^-1 . Calibration is completed by calculation of the transformation matrix T ₂ and the inverse transformation matrix T ₂ '.

Thereafter, the adjustment unit 203 performs the same adjustment as in the first embodiment using the inverse transformation matrix T ₂ '.

In the first to seventh embodiments described above, LED light other than the laser light for processing has been used for calibration. The reason for this is to prevent the workpiece 102 from being affected by irradiation of light for calibration.

Therefore, even if irradiated, the laser beam can be weakened to such an extent that the workpiece 102 is not affected. In another embodiment, when the laser beam is a light of a wavelength at which the CCD camera 112 can pick up the image, . In this case, the LED light source 116 and the half mirror 104 shown in Fig. 1 become unnecessary.

However, depending on the characteristics of the laser beam or the workpiece 102, it may not be preferable to use laser light for calibration or to use laser light for calibration.

Therefore, considering the influence of the light used for calibration and the light used for processing in different light sources from different light sources, in fact, there is an implied premise in the above-described first to seventh embodiments, When the premise is not established, there is room for more precise correction.

This tentative premise is that the optical axis of the laser beam when the laser beam passes through the half mirror 104 and enters the mirror 105 in FIG. 1 and the optical axis of the laser beam when the LED light is reflected by the half mirror 104, It is assumed that the optical axes of the LED light at the time of incidence coincide. Or, even if they do not completely match, it is assumed that there is only a slight deviation that is negligible.

However, this implicit assumption can not always be established. Therefore, in the eighth embodiment, in the case where this assumption is not satisfied, the light source optical system including the laser oscillator 103, the half mirror 104, the mirror 105 and the LED light source 116 in FIG. 1 As for the modification to which the output pattern is subjected, the correction amount is further refined as an object to be corrected.

14 is a functional block diagram for explaining the function of the control unit 113 in the eighth embodiment. Fig. 14 differs from Fig. 2 in that a second calculation section 208 is added. The second calculation section 208 calibrates the shift of the optical axis between the LED light and the laser light.

The eighth embodiment adopts the following mathematical model.

The conversion from the input pattern to the output pattern when the LED light source 116 is selected as the light source is an affine transformation.

This transformation is represented by the transformation matrix T of equation (2).

With the first output pattern corresponding to an input pattern and the laser oscillator 103 as a light source selected with the LED light source 116 selected as the light source, a deviation in the second output pattern corresponding to the same input pattern have. This shift is also modeled by affine transformation.

The shift parameter indicating the shift between the first output pattern and the second output pattern is represented by the transformation matrix R shown in Equation 36 in the same format as the transformation matrix T. [ That is, the first output pattern is converted into the second output pattern by the conversion matrix R.

[Formula 36]

The point in the coordinate (x, y) ^T in the input pattern is converted into the coordinate (x ", y") ^T in the output pattern when the laser oscillator 103 is selected as the light source. The relationship between these two coordinates is Equation 37.

[Formula 37]

According to the above mathematical model, in the eighth embodiment, the first calibration for obtaining the conversion matrix T and the inverse transformation matrix T ', the second calibration for obtaining the conversion matrix R and the inverse transformation matrix R' = R- ¹ , T 'and an inverse transformation matrix R'.

The first calibration for obtaining the transformation matrix T and the inverse transformation matrix T 'is the same as in the first embodiment.

The second calibration for obtaining the transformation matrix R and the inverse transformation matrix R 'is performed as follows. First, the second calculation unit 208 selects appropriate three points a, b, and c, and creates a calibration pattern capable of distinguishing the three points a, b, and c from each other. This calibration pattern may be the same as the example of Fig. Hereinafter, the calibration pattern in the second calibration is referred to as a "test pattern" in order to distinguish it from the calibration pattern in the first calibration.

The coordinates of the three points a, b,

(x _a , y _a ) ^T and (x _b , y _b ) ^T and (x _c , y _c ) ^T

As shown in FIG.

The second calculation unit 208 outputs the test pattern to the spatial modulation control unit 204. [ The DMD 106 is controlled by the spatial modulation control unit 204 in the state where a sample of the same type as the workpiece 102 to be machined is mounted on the stage 101 and irradiation of the LED light based on the test pattern is controlled And irradiation with laser light are performed. The switching of the light source is performed by the selection unit 206. [ The order of the investigation is arbitrarily set.

The selection unit 206 selects the LED light source 116 as the light source and when the LED light is irradiated on the sample, the CCD camera 112 picks up the sample and the picking unit 201 receives the picked-up image. The points corresponding to the points a, b, and c are referred to as a ', b', and c 'in the output pattern generated in the image corresponding to the test pattern, and the coordinates of these three points a', b ', and c'

(x _a ', y _a ') ^T and (x _b ', y _b ') ^T and (x _c ', y _c ') ^T

As shown in FIG.

When the selection unit 206 selects the laser oscillator 103 as a light source and the laser beam is irradiated onto the sample, the CCD camera 112 picks up an image of the sample, and the picking unit 201 receives the picked- . The points corresponding to the points a, b and c are referred to as a ", b ", and c "in the output pattern generated in the image corresponding to the test pattern, and the coordinates of these three points a ", b &

_{(x a ", y a"} ) T and _{(x b ", y b"} ) T and _{(x c ", y c"} ) T

As shown in FIG.

In the same manner as the calculation unit 202 calculates the transformation matrix T from the matrix P and the matrix Q, in the first embodiment, the second calculation unit 208 calculates three points a ' the second calculation unit 208 calculates the inverse transformation matrix R 'from the transformation matrix R by calculating the transformation matrix R from the coordinates of b', c 'and 3 points a ", b", c " Thus, the second calibration is completed.

The adjustment in the eighth embodiment is similar to the first embodiment in that the adjustment unit 203 converts the DMD transmission data and the spatial modulation control unit 204 uses the converted DMD transmission data as an input pattern to perform DMD (106).

In the eighth embodiment, the adjustment unit 203 performs the transformation using the inverse transformation matrix T 'and the matrix (T' R ') of the inverse transformation matrix R' in the first embodiment, while the transformation using the inverse transformation matrix T 'is performed in the first embodiment . With this conversion, it is confirmed as follows whether or not the desired portion is irradiated with the laser beam accurately.

It is assumed that a point p of coordinates (x _p1 , y _p1 ) ^T is included in a portion to be irradiated with light in the irradiation pattern designated by the operator from the operation unit 114 in the same manner as in the first embodiment. As a result of the adjustment by the adjustment unit 203, the point p is converted into the coordinate (x _p2 , y _p2 ) _T represented by the equation 38 in the input pattern instructed to the DMD 106 by the spatial modulation control unit 204 .

[Equation 38]

(x _p2 , y _p2 , 1) ^T = T 'R' (x _p1 , y _p1 , 1) ^T

Here, when the laser oscillator 103 is selected as the light source, the coordinate of the point on the output pattern corresponding to the coordinate (x _p2 , y _p2 ) ^T in the input pattern is (x _p3 , y _p3 ) ^T. Then equation 39 is derived from equation 37 and equation 38.

[Equation 39]

(x _p3 , y _p3 , 1) ^T

= RT (x _p2 , y _p2 , 1) ^T

RTT'R = _'(p1 x, _p1 y, 1) ^T

= (x _p1 , y _p1 , 1) ^T

That is, as a result of the adjustment by the adjustment unit 203, the coordinates specified on the irradiation pattern that the laser beam should be irradiated coincide with the coordinates on the output pattern indicating the position where the laser beam is actually irradiated, .

Next, the ninth embodiment will be described. The ninth embodiment is an example in which the present invention is applied to a projector using a spatial modulation element. In the projector (illumination optical system) for spatially modulating light from a projection light source with a spatial modulation element such as a DMD and projecting characters, symbols, pictures, images and the like on a wall or a screen, Can be applied.

Rotation, enlargement, reduction, unevenness, or the like may occur on the projected image without the light being projected to the designated shape and the specified position as the result of the shift or unevenness existing in the optical system or the screen. Thus, in the ninth embodiment, the above-described projector includes an image pickup section for picking up a screen and a control section. The image pickup unit is, for example, a CCD camera. The control unit has the same function as the taking unit 201, the calculating unit 202, the adjusting unit 203, and the spatial modulation controlling unit 204 in Fig.

According to the projector thus configured, calibration can be performed in the same manner as in each of the above-described embodiments, and projection adjusted according to the result of calibration can be performed. Since the ninth embodiment refers to the projector, the term "projection" is used, but the term " projection "in the ninth embodiment of the present invention is not limited to the" It means the same.

The present invention is not limited to the above-described embodiments, but may be modified in various ways. Some examples are described below.

The physical configuration of the laser processing apparatus 100 is not limited to the configuration illustrated in FIG. For example, a transmission type spatial modulation device using a liquid crystal may be used instead of the DMD 106 as a reflection type spatial modulation device. That is, the first light to be adjusted and irradiated and the second light used for calibration to obtain the data necessary for adjustment are subjected to spatial modulation with the spatial modulation element and irradiated onto the workpiece 102, ), The specific configuration of the laser machining apparatus 100 may be different according to the embodiment. Further, the first light and the second light may be different or the same.

2, only the spatial modulation control section 204, the stage control section 205, and the selection section 206 are mounted in the control section 113 of the laser processing apparatus 100 in Fig. 1 The take-in unit 201, the calculating unit 202 and the adjusting unit 203 in Fig. 2 may be realized by a computer outside the laser processing apparatus 100. Fig.

The adjusting method is not limited to the example described above. For example, in the second embodiment, an adjustment is made to cause the stage control unit 205 to move the stage 101 based on an instruction from the adjustment unit 203. [ In another embodiment, adjustment may be performed by changing the position or angle of the DMD 106 instead of the stage 101. [

That is, even if an actuator for changing the angle or position is mounted on the DMD 106 and the configuration shown in Fig. 2 is modified so that the spatial modulation control unit 204 also controls the actuator in addition to designation of the input pattern do. In this case, the adjustment unit 203 may instruct the spatial modulation control unit 204 to move the DMD 106 in accordance with the inverse transformation matrix T '. Due to the movement of the DMD 106, the shot position of the laser beam shifts in parallel (shifts), rotates around a certain point, or the size and shape of the irradiated area change.

The above-described plurality of embodiments can be arbitrarily combined as long as they do not contradict each other. For example, three or more embodiments may be combined as follows.

In the seventh embodiment in which a calibration pattern is formed to avoid unevenness on the workpiece 102,

A second calculation section 208 similar to the eighth embodiment, which is the object of calibration of the deviation of the optical axis between the laser light and the LED light,

Employs a pseudo-affine transformation of the sixth embodiment as a mathematical model,

Under the above mathematical model, the second calculation section 208 calculates the conversion matrix R and the inverse transformation matrix R 'for considering the shift of the optical axis of the laser light and the LED light by a method similar to the eighth embodiment

Instead of adjusting the data for DMD transfer to the spatial modulation control unit 204, the adjustment unit 203 performs adjustment by modifying an image for designating an irradiation pattern in the same manner as in the third embodiment.

Further, the timing of performing the calibration varies according to the embodiment. Therefore, in the description of each of the embodiments described above, in addition to the order of calibration after calibration, the timing of calibration is not particularly mentioned.

Describing with the example of the first embodiment, calibration may be performed only once when the laser processing apparatus 100 is used for the first time, and thereafter, irradiation of the laser light may be adjusted based on the same inverse transformation matrix T '. Or, calibration may be performed periodically to cope with changes in the laser processing apparatus 100 over time.

Alternatively, one workpiece 102 may be calibrated once. Of course, when a plurality of portions of one workpiece 102 are processed by the laser machining apparatus 100, calibration may be performed for each portion to be machined.

For example, if the workpiece 102 is a large FPD substrate and the stage 101 is a floating stage using an air caster, the workpiece 102 may be warped. In this case, due to the effect of the warp, the position of the object to be processed on the FPD substrate can be determined by the positional relationship between the workpiece 102 and the optical system (for example, objective lens 110) Distances are different.

The magnitude of the magnification of the light irradiated through the DMD 106 and the magnitude of the misalignment change in accordance with the variation of the distance although the distance between the work 102 and the optical system is very small. Therefore, in the case where high-precision adjustment taking into consideration the influence of such a small fluctuation is required, calibration may be performed for each target portion to be machined.

The relationship between the area on the workpiece 102 to which the calibration pattern is irradiated and the area on the workpiece 102 to which the irradiation pattern adjusted to be processed is irradiated also varies according to the embodiment.

For example, the case where the workpiece 102 is a substrate will be described as an example. In the case where the calibration is performed only once, or periodically, it is preferable to perform calibration using any substrate of the same type as the substrate to be processed.

When one substrate is calibrated once, if there is a margin at the end of the substrate, this margin may be used for calibration. That is, the control section 113 controls the laser processing device so that the laser is irradiated with the laser light adjusted according to the result of the calibration after the stage 101 is moved to the position where the margin is irradiated with the LED light, (100) may be controlled.

Alternatively, when performing calibration once or plural times with respect to one substrate, the controller 113 controls the laser machining apparatus 100 so that the calibration is performed after the stage 101 is moved to the position where the laser light is irradiated to the portion to be processed, (100) may be controlled. In this case, it is preferable to use LED light different from the processing laser light or laser light whose output is weakened for calibration so that the workpiece 102 is not affected by the calibration.

In addition, the present invention can be modified in various ways. For example, the process steps shown in the flowchart of Fig. 5 can be changed in various ways.

For example, the processing of step S102 and the processing of steps S103 to S105 can be executed independently and in parallel. Therefore, the processing of steps S103 to S105 may be executed simultaneously with the processing of step S102, or the processing may be executed in the order of steps S103, S104, S105, and S102.

Further, the same one calibration pattern may be used in a plurality of calibrations. In this case, the calculation unit 202 may store the calibration pattern in the storage device when the calibration pattern is created in the step S1O1 of the first calibration. Then, in the second or later calibration step S101, the calculation unit 202 may read the calibration pattern from the storage device.

In addition, the calibration pattern is created based on the coordinates of the three points a, b, and c determined first. Therefore, it is not necessary to acquire the coordinates of the three points a, b, and c again in step S102, and step S102 can be omitted. In other words, when calculating the calibration pattern, the calculating unit 202 may also store the coordinates of the three points a, b, and c in the storage device, and read the coordinates of the three points from the storage device in step S106.

Further, as in the second embodiment, in the embodiment in which the inverse transformation matrix T 'is not used for adjustment, the last step S107 is unnecessary.

Although the various embodiments have been described above, the effects common to the above-described embodiments will be described as follows.

Light can be irradiated onto the workpiece 102 in accordance with an arbitrary calibration pattern using a spatial modulation element such as the DMD 106. [ That is, the positions of a plurality of points can be represented by a single calibration pattern, and the calibration can be performed efficiently at one time.

Further, mechanical movement of the optical system or the stage 101 and irradiation of light need not be repeated for calibration. Therefore, for example, the influence of the error included in the operation of the actuator for mechanically moving the physical arrangement of the optical system can be excluded and calibration can be performed.

In addition, since the shape of the calibration pattern is arbitrary, it is easy to obtain a calibration pattern of an appropriate shape according to the properties of the workpiece 102 used for calibration. Here, the "property of the workpiece 102 " refers to various properties such as a three-dimensional shape and a material. Further, in order to obtain a calibration pattern of an appropriate shape, an appropriate calibration pattern may be selected from among a plurality of calibration patterns previously prepared and stored, or an appropriate calibration pattern may be created on the spot.

For example, as described in connection with the seventh embodiment, when there is a three-dimensional structure in which the shape of the calibration pattern is distorted in a region on the workpiece 102 to which light is to be irradiated according to a certain calibration pattern, Is not recommended. In this case, it is preferable to use another calibration pattern for irradiating light to the structure.

As in the seventh embodiment, even if no information is given in advance, a calibration pattern of a proper shape is formed on the spot so that the three-dimensional structure on the workpiece 102 is avoided based on the image captured by the CCD camera 112 And may be generated by the creating unit 207. [

In addition, the seventh embodiment may be modified so that preliminary calibration is not always performed but preliminary calibration is performed only when necessary. For example, during the execution of the calibration, only when the calculating section 202 detects the unevenness of the output pattern that is considered to be attributable to the unevenness on the surface of the workpiece 102 and the unevenness is detected, according to the seventh embodiment , The calibration pattern may be set again.

Alternatively, in an embodiment other than the seventh embodiment, the calculating unit 202 may acquire information such as design data of the workpiece 102 in advance, extract a range of the background unit from the design data, A calibration pattern to be irradiated may be generated. In either case, since the correction amount pattern is arbitrary, an appropriate correction pattern can be easily found by the creating unit 207 or the calculating unit 202. [

When a workpiece 102 is made of a plurality of materials having different reflectances of light, an appropriate calibration pattern is obtained so that light is irradiated from a region where a material having a low reflectance of light is used, May be used. It is possible to easily acquire an appropriate calibration pattern based on an image or based on design data as in the seventh embodiment.

Thus, even when the workpiece 102 having a possibility of lowering the accuracy of the calibration is used, it is easy to acquire and use an appropriate calibration pattern according to the property of the workpiece 102, Improvement can be achieved.

In addition, in the conventional techniques described in Patent Documents 1 to 3, the object of calibration is limited, and for example, rotation, non-uniformity, or scale conversion is not considered in some cases. However, in the embodiment of the present invention, calibration can be performed according to the mathematical model appropriately selected according to the required accuracy of calibration or the characteristics of the apparatus to be calibrated (for example, the laser processing apparatus 100).

This is because, since the calibration pattern is arbitrary, various mathematical models can be adopted as compared with the conventional technique. Thus, if a more precise mathematical model is employed, various factors are taken into account and more precise adjustments are made.

The mathematical model for calibration may be other than the above-mentioned examples. For example, a mathematical model that is modified differently by regions may be employed. That is, the image captured by the CCD camera 112 is divided into a plurality of regions, the calculation unit 202 calculates the inverse transformation matrix T 'and the inverse transformation matrix T' for each region, and based on the inverse transformation matrix T ' (203) may perform adjustment.

Fig. 1 is a schematic view showing a configuration of a laser machining apparatus in the first embodiment. Fig.

2 is a functional block diagram showing functions of the control unit in the first embodiment.

Fig. 3 is a diagram illustrating deformation of an irradiation pattern caused by misalignment or unevenness existing in the laser processing apparatus.

4 is a diagram showing an example of a calibration pattern.

5 is a flowchart showing a step of calculating conversion parameters in the first embodiment.

6 is a diagram for explaining an adjustment method in the first embodiment.

7 is a diagram for explaining an example of conversion from an input pattern to an output pattern.

8 is a functional block diagram showing functions of the control unit in the second embodiment.

9 is a view for explaining an adjustment method in the second embodiment.

10 is a functional block diagram showing functions of the control unit in the third embodiment.

11 is a view for explaining an adjustment method in the third embodiment.

12 is an example of an image when a calibration pattern is examined in the seventh embodiment.

13 is a functional block diagram showing functions of the control unit in the seventh embodiment.

14 is a functional block diagram showing functions of the control unit in the eighth embodiment.

DESCRIPTION OF THE REFERENCE NUMERALS

100: laser processing apparatus 101: stage

102: workpiece 103: laser oscillator

104, 107, 109: half mirror 105: mirror

106: DMD 108: imaging lens

110: objective lens 111: illumination light source

112: CCD camera 113:

114: Operation part 115: Monitor

116: LED light source 201:

202: Calculator 203:

204: spatial modulation control unit 205: stage control unit

206: selection unit 207:

208: second calculating unit 300 to 304:

310 to 312: Survey pattern 320, 321: Data for DMD transmission

330 to 334: Live image 340 to 342: Calibration pattern

401: substrate 402: circuit pattern

403-405: won

Claims (13)

An adjusting device for adjusting irradiation of an object with light spatially modulated by a spatial modulation element according to a designated input pattern, A blowing unit for receiving an image of the object irradiated with the light that has been spatially modulated by the spatial modulation element, A calculation section for calculating an output pattern corresponding to the input pattern on the image and a conversion parameter for converting the input pattern into the output pattern, Wherein said input parameter is a value obtained by subtracting, as said input pattern, said conversion parameter according to an irradiation pattern designated to said spatial modulation element, based on said conversion parameter calculated by said calculation section when using a calibration pattern which is a reference pattern indicating coordinates of at least one point used for calibration An adjustment unit for adjusting the irradiation of light to the object &Lt; / RTI &gt; The method according to claim 1, The transformation parameters are represented by a matrix, The method according to claim 1, The adjustment unit calculates an inverse transformation parameter indicating inverse transformation of the transformation by the transformation parameter, and performs adjustment based on the inverse transformation parameter. The method of claim 3, And the adjustment unit performs adjustment by designating a second irradiation pattern obtained by converting the irradiation pattern into the inverse conversion parameter as the input pattern. The method of claim 3, The adjustment unit obtains a second image by converting a first image obtained by imaging the object into the inverse transformation parameter and provides the second image as an image used for indicating a position for specifying the irradiation pattern . The method of claim 3, And the adjusting section adjusts at least one of a position and a direction of the spatial modulation element based on the inverse transformation parameter. The method according to claim 1, And the adjusting unit adjusts at least one of a position and a direction of the object based on the conversion parameter. The method according to claim 1, Further comprising a creating section that creates the calibration pattern based on information of the surface of the object so that the light is irradiated to the background portion of the surface of the object when the calibration pattern is designated as the input pattern. 9. The method of claim 8, Wherein the creating unit comprises: Designating a preliminary calibration pattern as the input pattern, calculating a second conversion parameter in the calculation unit, A second inverse transformation parameter indicating an inverse transformation of the transformation represented by the second transformation parameter, Detecting the background area in which the background is imaged in the image for background detection in which the object is imaged and creating the correction pattern using the second inverse transformation parameter so that light is irradiated on the background part based on the background area , Adjusting device. The method according to claim 1, A selector for selecting one of the first light source and the second light source so that light emitted from one of the first light source and the second light source is incident on the spatial modulation element; Further comprising a second calculating section that calculates a shift parameter indicative of a shift occurring in the output pattern depending on whether one of the first light source and the second light source is selected when the test pattern is designated as the input pattern, Wherein the selection unit selects the first light source as a light source of light to be irradiated in accordance with the calibration pattern, The adjustment unit adjusts the irradiation of light from the second light source to the object in accordance with the irradiation pattern based on both the parameters of the conversion parameter and the displacement parameter in a state in which the second light source is selected, Adjusting device. An optical system for guiding the laser light emitted from the laser light source onto an object, A spatial modulation element provided on the optical path from the laser light source to the object, for spatial modulation of incident light, An apparatus as claimed in any one of the preceding claims, The method according to claim 1, wherein the laser light is used as light to be irradiated onto the object, And the irradiation of the laser beam to the object is adjusted by the adjustment device to process the object. Computer, Receiving an image of an object irradiated with light that has been spatially modulated by the spatial modulation element according to a specified calibration pattern, Calculating a pattern generated corresponding to the calibration pattern on the image and a conversion parameter for converting the calibration pattern, And irradiating light to the object in accordance with the irradiation pattern designated to the spatial modulation element based on the conversion parameter Adjustment method. Receiving an image of an object irradiated with light that has been spatially modulated by the spatial modulation element according to a specified calibration pattern, Calculating a pattern that corresponds to the calibration pattern on the image and a conversion parameter for converting the calibration pattern; Adjusting irradiation of light to the object in accordance with an irradiation pattern designated to the spatial modulation element based on the conversion parameter Readable storage medium storing an adjustment program for causing a computer to execute the program.

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