JP2010264461A - Laser beam machining method, laser beam machining apparatus and method for manufacturing solar panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform the scribe processing by optimizing the optical axis of laser beam on the real time basis. <P>SOLUTION: Laser beam generated from a laser beam generator is reflected by a plurality of mirror means, and introduced to a machining position. When a large workpiece is irradiated with laser beam, the mirror means may be moved together with a laser beam head. In such a case, the optical axis of the laser beam may be deviated. In the present invention, a part of laser beam is branched and extracted, the deviation of the optical axis is detected based on the extracted laser beam, the reflecting direction of the mirror means is controlled based on the result of the detection, and optimized so as to reduce the deviation of the optical axis. The deviation of the optical axis of the laser beam is detected by using a quadripartite photodiode means. A biaxial type galvano mirror means or two galvano mirror means with their driving shafts being orthogonal to each other are used for a mirror means for controlling the reflecting direction of the laser beam. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a laser processing method, a laser processing apparatus, and a solar panel manufacturing method for processing a thin film or the like using laser light, and in particular, a laser capable of optimizing by correcting the deviation of the optical axis of laser light in real time. The present invention relates to a processing method, a laser processing apparatus, and a solar panel manufacturing method.

  Conventionally, in a solar panel manufacturing process, a transparent electrode layer, a semiconductor layer, and a metal layer are sequentially formed on a translucent substrate (glass substrate), and each layer is processed into a strip shape with laser light in each step after the formation. A solar panel module has been completed. When manufacturing a solar panel module in this manner, scribe lines are formed on a thin film on a glass substrate with laser light at a pitch of about 10 mm, for example. The scribe line has a line width of about 30 μm, and is composed of three lines such that the distance between the lines is about 30 μm. When forming a scribe line with a laser beam, the laser beam is usually irradiated onto a glass substrate that moves at a constant speed. As a result, it was possible to form a scribe line having a stable depth and line width. As a method for manufacturing such a solar panel (photoelectric conversion device), the one described in Patent Document 1 is known.

JP 2006-054254 A

In the method for manufacturing a solar panel (photoelectric conversion device) described in Patent Document 1, a scribe line is formed using a multimode laser beam, that is, a laser beam having a substantially trapezoidal power distribution, rather than a single mode laser beam. According to this document, it is described that high electrical insulation is ensured. When the optical axis of the laser beam is shifted in the process of manufacturing the solar panel, conventionally, the laser beam is visually checked after the laser processing to determine the optical axis shift as it is. In recent years, with the increase in the size of the solar panel, the manufacturing apparatus itself has also increased in size, and the member that supports the laser beam head section during the laser processing has been bent and deformed, and the laser beam emitted from the laser beam generation apparatus has been deformed. There was a problem that the optical axis shifted.
The object of the present invention has been made in view of the above points, and provides a laser processing method, a laser processing apparatus, and a solar panel manufacturing method capable of performing scribing by optimizing the optical axis of laser light in real time. It is to be.

A first feature of the laser processing method according to the present invention is that the laser is used by using mirror means at the time of laser processing for performing predetermined processing on the work by irradiating the work while moving the laser beam relatively to the work. A part of the laser beam is branched and extracted in the optical path when the light is reflected and introduced to the processing position, and the deviation of the optical axis of the laser beam is detected based on the extracted laser beam. According to the result, the reflection direction of the laser beam of the mirror means positioned before the branch extraction is controlled.
Laser light generated from the laser generator is reflected by a plurality of mirror means and introduced to a processing position. When irradiating a large workpiece with laser light, the mirror means may move together with the laser light head. In such a case, the optical axis of the laser beam may be shifted. Therefore, in the present invention, a part of the laser beam is branched and extracted, the amount of deviation of the optical axis is detected based on the extracted laser beam, and the reflection direction of the mirror means is controlled variously based on the detection result to thereby change the optical axis. The amount of deviation is reduced and the optical axis is optimized in real time.

A second feature of the laser processing method according to the present invention resides in that, in the laser processing method according to the first feature, a deviation of the optical axis of the laser light is detected using a four-division photodiode means.
The quadrant photodiode receives a part of the branched laser light (sampling beam) near the center of the light receiving surface and outputs four types of signals corresponding to the intensity of the laser light detected on each light receiving surface. . Based on these four types of signals, the reflection direction of the mirror means can be easily controlled.

A third feature of the laser processing method according to the present invention is the laser processing method according to the first or second feature, wherein the mirror means for controlling the reflection direction of the laser light is a biaxial galvanometer mirror. This means that two galvanometer mirror means having orthogonal means or drive axes are used.
This uses a galvanometer mirror means for controlling the reflection direction of the laser beam. As the galvanometer mirror means, a two-axis type may be used, or the drive axes of the two galvanometer mirror means may be orthogonal to each other. By using the galvanometer mirror means, the reflection direction of the laser light can be easily controlled.

  A first feature of the laser processing apparatus according to the present invention is that a holding unit that holds a workpiece, a laser beam irradiation unit that irradiates the workpiece with a laser beam to perform a predetermined processing process, and reflects the laser beam. Mirror means for introducing to the laser light irradiation means; extraction means for branching and extracting a part of the laser light in the optical path of the laser light; and light receiving means for receiving the laser light extracted by the extraction means; Detection means for detecting a deviation of the optical axis of the laser light based on a signal from the light receiving means, and the laser light of the mirror means positioned before the extraction means according to the detection result of the detection means And a control means for controlling the reflection direction. This is an invention of a laser processing apparatus corresponding to the first feature of the laser processing method.

  A second feature of the laser processing apparatus according to the present invention is that, in the laser processing apparatus according to the first feature, the detection means is constituted by a four-division photodiode means. This is an invention of a laser processing apparatus corresponding to the second feature of the laser processing method.

  According to a third feature of the laser processing apparatus of the present invention, in the laser processing apparatus according to the first or second feature, the mirror means for controlling the reflection direction of the laser light is a biaxial galvanometer mirror means. Alternatively, it is constituted by two galvanometer mirror means whose drive axes are orthogonal to each other. This is an invention of a laser processing apparatus corresponding to the third feature of the laser processing method.

  The solar panel manufacturing method according to the present invention is characterized by using the laser processing method according to the first, second, or third feature or the laser processing apparatus according to the first, second, or third feature. To manufacture solar panels. In this method, a solar panel is manufactured using either the laser processing method or the laser processing apparatus.

  According to the present invention, there is an effect that scribing can be performed by optimizing the optical axis of laser light in real time.

It is a figure which shows schematic structure of the laser processing apparatus which concerns on one embodiment of this invention. It is a figure which shows the schematic structure of the light-receiving surface of a 4-part dividing photodiode, and the irradiation state of a laser beam. It is a figure which shows the detailed structure of the optical system member of FIG. It is a schematic diagram which shows the structure of the detection optical system member of FIG. It is a block diagram which shows the detail of a process of a control apparatus. It is a figure which shows an example of operation | movement of the pulse missing determination means of FIG. It is a figure which shows an example of the waveform output from the high-speed photodiode of FIG. It is the figure which looked at the optical system member of Drawing 1 from the lower side (work side). It is a figure which shows the relationship between the rotation amount of an optical system member, and the pitch width of a scribe line.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a laser processing apparatus according to an embodiment of the present invention. This laser processing apparatus performs a laser beam processing (laser scribing) process of a solar panel manufacturing apparatus.

  The solar panel manufacturing apparatus in FIG. 1 includes a pedestal 10, an XY table 20, a laser generator 40, an optical system member 50, an alignment camera device 60, a linear encoder 70, a control device 80, a detection optical system member, and the like. An XY table 20 that is driven and controlled along the X-axis direction and the Y-axis direction (XY plane) of the pedestal 10 is provided on the pedestal 10.

  The XY table 20 is controlled to move in the X direction and the Y direction. In addition, although a ball screw, a linear motor, etc. are used as a drive means of the XY table 20, these illustration is abbreviate | omitted. On the upper side of the XY table 20, a workpiece 1 to be laser processed is held. A slide frame 30 that is slid in the Y-axis direction while holding the optical system member is provided on the base 10. The XY table 20 is configured to be rotatable in the θ direction about the Z axis. Note that when the amount of movement in the Y-axis direction can be sufficiently secured by the slide frame 30, the XY table 20 may be configured to only move in the X-axis direction. In this case, the XY table 20 may have an X-axis table configuration.

  The slide frame 30 is attached to a movable table provided at four corners on the base 10. The slide frame 30 is controlled to move in the Y direction by this moving table. A vibration isolation member (not shown) is provided between the base plate 31 and the moving table. A laser generator 40, an optical system member 50, and a control device 80 are installed on the base plate 31 of the slide frame 30. The optical system member 50 is constituted by a combination of a mirror and a lens, and divides the laser beam generated by the laser generator 40 into four lines and guides it onto the work 1 on the XY table 20. Note that the number of divisions of the laser light is not limited to four, but may be two or more.

  The alignment camera device 60 acquires images near the both end portions (front and rear edge portions in the X-axis direction) of the work 1 on the XY table 20. An image acquired by the alignment camera device 60 is output to the control device 80. The control device 80 stores the image from the alignment camera device 60 in the database unit together with the ID data of the workpiece 1 and uses it for the subsequent alignment processing of the workpiece 1.

  The linear encoder 70 includes a scale member and a detection unit provided on the side surface of the X-axis movement table of the XY table 20. The detection signal of the linear encoder 70 is output to the control device 80. The control device 80 detects the moving speed (moving frequency) in the X-axis direction of the XY table 20 based on the detection signal from the linear encoder 70 and controls the output (laser frequency) of the laser generator 40.

  As illustrated, the optical system member 50 is provided on the side surface side of the base plate 31 and is configured to move along the side surface of the base plate 31. The tip of the optical system member 50 is rotatable around the Z axis. A galvanometer mirror 33 for guiding laser light emitted from the laser generator 40 to the optical system member 50 is provided on the base plate 31. The galvanometer mirror 33 uses two motors (rotary encoders) to scan the XZ two-dimensional area with laser light. The galvanometer mirror 33 is composed of a two-axis type (X, Z), and is composed of two motors and a mirror attached to the motor. The galvano control device 331 includes a driver and a power source for moving the motor, a microcomputer for controlling them, and the like.

  The mirrors 34 and 35 are provided on the optical system member 50 and are interlocked with the slide movement of the optical system member 50. The laser light emitted from the laser generator 40 is reflected toward the mirror 34 by the galvano mirror 33, and the laser light toward the mirror 34 is reflected toward the mirror 35 by the mirror 34. The mirror 35 guides the reflected laser light from the mirror 34 into the optical system member 50 through a through hole provided in the base plate 31. The laser light emitted from the laser light generating device 40 may have any configuration as long as the laser light is configured to be introduced from above into the optical system member 50 through a through hole provided in the base plate 31. It may be. For example, the laser generator 40 may be provided on the upper side of the through hole, and the laser beam may be directly guided to the optical system member 50 through the through hole.

  The beam sampler 332 is provided on the optical system member 50 between the galvanometer mirror 33 and the reflection mirror 34 so as to move along with the sliding movement of the optical system member 50. The beam sampler 332 is an element that samples a part of the laser beam (for example, about 10% of the laser beam or less) and branches and outputs it to the outside. The quadrant photodiode 333 is arranged so as to receive a part of the laser beam (sampling beam) branched by the beam sampler 332 in the vicinity of the center of the light receiving surface. Four types of output signals corresponding to the intensity of the laser light detected by the four-division photodiode 333 are output to the galvano control device 331. The galvano control device 331 controls the two motors 33xy and 33yz of the galvano mirror 33 in real time according to the four types of output signals from the four-division photodiode 333. The motor 33xy controls the reflected laser beam of the galvanometer mirror 33 to rotate in a plane parallel to the upper surface (XY plane) of the base plate 31, and the motor 33zy controls the reflected laser beam of the galvanometer mirror 33 to the base plate 31. Control is performed in real time so as to rotate and move in a plane parallel to a plane (YZ plane) orthogonal to the upper surface of.

  FIG. 2 is a diagram showing a schematic configuration of a light receiving surface of a four-divided photodiode and a laser light irradiation state. As shown in FIG. 2, the quadrant photodiode 333 has four light receiving surfaces 333a to 333d that are equally divided. A line connecting the centers of the light receiving surfaces 333a and 333c corresponds to the upper surface (XY plane) of the base plate 31, and a line connecting the centers of the light receiving surfaces 333b and 333d is orthogonal to the upper surface of the base plate 31. It is provided so as to correspond to (YZ plane). The voltage Va is output from the light receiving surface 333a, the voltage Vb is output from the light receiving surface 333b, the voltage Vc is output from the light receiving surface 333d, and the voltage Vd is output from the light receiving surface 333d to the galvano control device 331. The galvano control device 331 constantly measures the differential voltage value (Va−Vc) between the voltage Va and the voltage Vc, and controls the drive of the motor 33xy of the galvano mirror 33 according to the differential voltage value, and the difference between the voltage Vb and the voltage Vd. The voltage value (Vb−Vd) is constantly measured, and the motor 33yz of the galvanomirror 33 is driven and controlled in real time according to the differential voltage value.

  As shown in FIG. 2A, when the laser beam 40a irradiates substantially the center of the four light receiving surfaces 333a to 333d and the light receiving surfaces 333a to 333d, the voltages Va to Vd are equal. Therefore, the difference value is 0. In this case, the two motors 33xy and 33yz of the galvano mirror 33 are not driven and controlled. The state shown in FIG. 2A is an ideal state. If this state can be maintained at the time of laser processing, there is no problem, but actually, as shown in FIG. 2B, the laser beam 40b is caused by the bending of the base plate 31 when the optical system member 50 slides. May be irradiated with the optical axis of the four-divided photodiode 333 shifted toward the light receiving surface 333c. In this case, the voltages Vb and Vd are substantially equal and the differential voltage value (Vb−Vd) is 0, but the voltage Va is smaller than the voltage Vc, and the differential voltage value (Va−Vc) is a negative value. . The galvano control device 331 drives and controls the motor 33xy of the galvano mirror 33 so that the differential voltage value (Va−Vc) becomes zero. Similarly, as shown in FIG. 2C, the optical axis of the laser beam 40c may be irradiated with being shifted to the light receiving surface 333b side of the quadrant photodiode 333. In this case, the voltages Va and Vc are substantially equal and the differential voltage value (Va−Vc) is 0, but the voltage Vb is larger than the voltage Vd, and the differential voltage value (Vb−Vd) is a positive value. . The galvano control device 331 drives and controls the motor 33 yz of the galvano mirror 33 in real time so that the differential voltage value (Vb−Vd) becomes zero. In the above-described embodiment, the biaxial (X, Z) galvanometer mirror 33 has been described as an example, but a uniaxial (X axis or Z axis) galvanometer mirror may be provided. Alternatively, the galvanometer mirror 33 may be configured by a normal mirror, and a biaxial (X, Z) galvanometer mirror may be provided at the position of the mirror 34. In this case, the beam sampler 332 is preferably provided between the mirror 34 and the mirror 35. Note that where the galvanometer mirror and the beam sampler are provided varies depending on the positional relationship between the laser generator and the optical system member, and it is preferable to consider the optimum position.

  FIG. 3 is a diagram illustrating a detailed configuration of the optical system member 50. Although the actual configuration of the optical system member 50 is complicated, the illustration is simplified here for the sake of simplicity. Note that FIG. 3 is an example, and the optical system components may be reduced more than this. FIG. 3 is a view of the inside of the optical system member 50 as viewed from the −X axis direction of FIG. 2. As shown in FIG. 3, the base plate 31 has a through hole 37 for introducing the laser beam reflected by the mirror 35 into the optical system member 50. A phase type diffractive optical element (DOE) 500 that converts laser light having a Gaussian intensity distribution into laser light having a top hat intensity distribution is provided directly below the through hole 37.

  The laser light converted into laser light having a top hat intensity distribution (top hat beam) by the DOE 500 is branched into a reflected beam and a transmitted beam by the half mirror 511, and the reflected beam is transmitted to the right half mirror 512. Advances toward the reflective mirror 524 in the downward direction. The beam reflected by the half mirror 511 is further split into a reflected beam and a transmitted beam by the half mirror 512, and the reflected beam travels toward the lower reflecting mirror 522, and the transmitted beam travels toward the right reflecting mirror 521. The beam that has passed through the half mirror 512 is reflected by the reflecting mirror 521, and is irradiated onto the work 1 through the condensing lens 541 in the downward direction. The beam reflected by the half mirror 512 is reflected by the reflection mirrors 522 and 523 and is irradiated onto the workpiece 1 through the condensing lens 542 in the downward direction. The beam transmitted through the half mirror 511 is reflected by the reflection mirror 524 and travels in the left direction. The beam reflected by the reflection mirror 524 is branched into a reflection beam and a transmission beam by the half mirror 513, the reflection beam travels toward the reflection mirror 526 in the downward direction, and the transmission beam travels toward the reflection mirror 528 in the left direction. The beam reflected by the half mirror 513 is reflected by the reflection mirrors 526 and 527 and is irradiated onto the work 1 through the condensing lens 543 in the downward direction. The beam that has passed through the half mirror 513 is reflected by the reflecting mirror 528, and is irradiated onto the work 1 through the condensing lens 544 in the downward direction.

  The top hat beam converted by the DOE 500 is transmitted and reflected by the above-described half mirrors 511 to 513 and the reflection mirrors 521 to 528 and guided to the condenser lenses 541 to 544. At this time, the optical path lengths from the DOE 500 to the condenser lenses 541 to 544 are set to be equal. That is, the optical path length from when the beam reflected by the half mirror 511 passes through the half mirror 512 and is reflected by the reflection mirror 521 to reach the condenser lens 541, and the beam reflected by the half mirror 511 is the half mirror 512 and the reflection mirror 522. , 523, the optical path length until reaching the condenser lens 542, and the beam transmitted through the half mirror 511 are reflected by the reflection mirror 523, the half mirror 513, the reflection mirrors 526 and 527, respectively, and enter the condenser lens 543. The optical path length until the beam reaches the condensing lens 544 is reflected by the reflection mirror 523, reflected by the reflection mirror 523, reflected by the reflection mirror 528, and reaches the condenser lens 544, respectively. Are equal distances. Accordingly, even if the DOE 500 is arranged immediately before the beam is branched, the laser light having the top hat intensity distribution can be similarly guided to the condenser lenses 541 to 544. Note that when processing is performed using laser light having a Gaussian intensity distribution, the number of optical components may be reduced, and the optical path lengths may not be equal.

  The shutter mechanisms 531 to 534 block the emission of laser light when the laser light emitted from the condenser lenses 541 to 544 of the optical system member 50 is detached from the work 1. The autofocus length measuring systems 52 and 54 are composed of a detection light irradiation laser and an autofocus photodiode (not shown), and are reflected from the surface of the work 1 in the light irradiated from the detection light irradiation laser. The reflected light is received, and the condensing lenses 541 to 544 in the optical system member 50 are driven up and down in accordance with the amount of reflected light to adjust the height relative to the work 1 (the focus of the condensing lenses 541 to 544). The focus adjustment drive mechanism is not shown.

  FIG. 4 is a schematic diagram showing the configuration of the first detection optical system member and the second detection optical system member. The first detection optical system member includes a condenser lens height measurement system 26 and a focus and optical axis adjustment CCD camera 28. In FIG. 4, the condenser lens height measuring system 26 and the focus and optical axis adjusting CCD camera 28 are shown in an overlapping manner, so that they are distinguished by reference numerals. When the height from the workpiece 1 to the lower surfaces on both sides of the optical system member 50 is adjusted by the autofocus length measuring systems 52 and 54 shown in FIG. 3, the height of the lower surface of the optical system member 50 is made the same. Even if it can, the height from the workpiece | work 1 to each condensing lens 541-544 cannot necessarily be made the same. Therefore, in this embodiment, the condenser lens height measuring system 26 is attached to either one of the side surfaces in the X-axis direction of the XY table 20 (the side surface in the −X-axis direction of the XY table 20 in the drawing). To the condensing lenses 541 to 544, respectively. A signal corresponding to the height of each of the condenser lenses 541 to 544 detected by the condenser lens height measuring system 26 is output to the control device 80. The control device 80 determines whether or not the height from the workpiece 1 to each of the condenser lenses 541 to 544 is appropriate. The arrangement (height) of the condenser lenses 541 to 544 is adjusted according to the length measurement result of the condenser lens height measuring system 26. In this case, the arrangement (height) of the condenser lenses 541 to 544 can be adjusted manually or automatically. If the height of the lower surface of the optical system member 50 is measured using the condensing lens height measuring system 26, the autofocus length measuring systems 52 and 54 can be omitted. .

  The focus and optical axis adjusting CCD camera 28 is one of the side surfaces in the X-axis direction of the XY table 20 (the side surface in the −X-axis direction of the XY table 20 in the figure), and is a condensing lens height measuring system. 26 adjacent positions (neighboring). The CCD camera 28 for focus and optical axis adjustment associates the positions of the XY table 20 and the respective condensing lenses 541 to 544 of the optical system member 50 and is installed so that the sky side of the XY table 20 can be seen. . The image captured by the focus and optical axis adjusting CCD camera 28 is output to the control device 80. The control device 80 determines whether or not the optical axis of the laser light emitted from each of the condenser lenses 541 to 544 is appropriate. In other words, the focus and optical axis adjusting CCD camera 28 can directly observe the laser light emitted from the respective condensing lenses 541 to 544 of the optical system member 50. By imaging this, the control device 80 Can determine whether the focus and the optical axis of each of the condenser lenses 541 to 544 are appropriate. Further, when each optical system related to the laser light such as the laser generator 40 and the optical system member 50 is replaced, the images before and after the replacement are acquired and digitized, so that the focus and optical axis after the replacement are obtained. Adjustment can be performed easily. Further, in the case of a plurality of heads, variation can be appropriately adjusted by acquiring and digitalizing images of the respective laser beams.

  As shown in FIG. 1, the second detection optical system member includes beam samplers 92 and 93, a high-speed photodiode 94, and an optical axis inspection CCD camera 96. The beam samplers 92 and 93 are provided in the optical path of laser light introduced into the optical system member 50. In this embodiment, it is provided between the laser generator 40 and the reflection mirror 33. The beam samplers 92 and 93 are elements that sample a part of the laser beam (for example, about 0.4% or less of the laser beam) and branch out the output. The high-speed photodiode 94 is disposed so as to receive a part (sampling beam) of the laser beam branched and output by the beam sampler 92 near the center of the light receiving surface. An output signal corresponding to the intensity of the laser light detected by the high speed photodiode 94 is output to the control device 80. The optical axis inspection CCD camera 96 is arranged so as to receive a part (sampling beam) of the laser beam branched and output by the beam sampler 93 near the center of the light receiving surface. The image captured by the optical axis inspection CCD camera 96 is output to the control device 80. The optical axis inspection CCD camera 96 may capture an image indicating the position of the laser light applied to the high-speed photodiode 94 and output the image to the control device 80.

  The control device 80 detects the moving speed (moving frequency) of the XY table 20 in the X-axis direction based on the detection signal from the linear encoder 70, controls the output (laser frequency) of the laser generator 40, and is a high-speed photodiode. 94 and the signal output from the optical axis inspection CCD camera 96 are used to detect missing pulses of the laser light emitted from the laser generator 40, or based on the amount of optical axis deviation of the laser light. The emission conditions are controlled, and the arrangement of the reflection mirrors 33 to 35 for introducing the laser light in the optical system member 50 is feedback-controlled.

  FIG. 5 is a block diagram showing details of processing of the control device 80. The control device 80 includes a branching unit 81, a missing pulse determining unit 82, an alarm generating unit 83, a reference CCD image storage unit 84, an optical axis deviation measuring unit 85, a laser controller 86, a lens displacement measuring unit 87, and a lens height adjustment. It comprises means 88, irradiation laser state inspection means 89, and irradiation laser adjustment means 8A.

  The branching unit 81 branches the detection signal (clock pulse) of the linear encoder 70 and outputs it to the laser controller 86 at the subsequent stage. The pulse missing determination means 82 receives an output signal (diode output) corresponding to the laser light intensity from the high-speed photodiode 94 and a detection signal (clock pulse) output from the branching means 81, and based on this, the laser light Determine missing pulses. FIG. 7 is a diagram illustrating an example of the operation of the missing pulse determination unit 82. 7A is an example of a detection signal (clock pulse) output from the branching unit 81, and FIG. 7B is an output signal (diode corresponding to the laser light intensity output from the high-speed photodiode 94. FIG. 7C shows an example of an alarm signal output by the missing pulse determination means 82 when a missing pulse is detected.

  As shown in FIG. 6, the pulse missing determining means 82 determines whether or not the diode output value is equal to or greater than a predetermined threshold value Th by using the falling edge of the clock pulse from the branching means 81 as a trigger signal. When the diode output value is smaller than the threshold value Th, a high level signal is output to the alarm generating means 83. The alarm generating unit 83 notifies the outside of the alarm indicating that a pulse missing has occurred when the signal from the pulse missing judging unit 82 changes from a low level to a high level. The alarm is notified by various methods such as image display and pronunciation. The occurrence of an alarm allows the operator to recognize that a pulse drop has occurred. If this alarm occurs frequently, it means that the performance of the laser generator has deteriorated or has reached the end of its life.

  The reference CCD image storage means 84 stores a reference CCD image 84a as shown in FIG. The reference CCD image 84a shows an image in a state where the laser beam is received at the center of the light receiving surface of the CCD camera 96 for optical axis inspection. The optical axis inspection CCD camera 96 outputs an inspection image 85a as shown in FIG. The optical axis deviation amount measuring means 85 captures the inspected image 85a from the optical axis inspection CCD camera 96, compares it with the reference CCD image 84a, measures the optical axis deviation amount, and calculates the deviation amount by the laser. Output to the controller 86. For example, when an image such as the inspected image 85a shown in FIG. 5 is output from the optical axis inspection CCD camera 96, the optical axis deviation measuring means 85 compares the X axis and the Y axis. The amount of direction deviation is measured and output to the laser controller 86. The laser controller 86 introduces the laser beam into a device related to the optical axis of the laser beam, that is, the emission condition of the laser generator 40 and the optical system member 50 so that the inspected image 85a and the reference CCD image 84a coincide. The arrangement and the like of the reflecting mirrors 33 to 35 are adjusted by feedback.

  The lens displacement amount measuring means 87 inputs a signal corresponding to the height of each of the condenser lenses 541 to 544 detected by the condenser lens height measuring system 26, and the height of each of the condenser lenses 541 to 544 is determined. It is determined whether it is within the allowable range or greatly deviated from this allowable range, and a control signal indicating how much the height of the condensing lenses 541 to 544 that are largely deviated should be adjusted is the lens height adjustment It outputs to the means 88. The lens height adjusting unit 88 adjusts the arrangement of the condenser lenses 541 to 544 in accordance with a control signal from the lens displacement amount measuring unit 87. When there is no height adjustment mechanism for the condensing lenses 541 to 544, the lens height adjusting unit 88 selects any of the condensing lenses 541 to 544 based on a control signal from the lens displacement amount measuring unit 87. The adjustment information may be transmitted to the operator (visual display, voice pronunciation, etc.).

  The irradiation laser state inspection unit 89 captures the image 89a from the CCD camera 28 for focus and optical axis adjustment, measures the shift amount of the focus and the optical axis based on this, and outputs the shift amount to the irradiation laser adjustment unit 8A. To do. For example, when an image 89a as shown in FIG. 6 is output from the focus and optical axis adjusting CCD camera, the irradiation laser state inspection unit 89 uses the circular outline 89b (the condensing lens 541 in the image 89a). The line of the focus circle 89c (small circle in the image 89a) is detected on the basis of (a line corresponding to the outer edge of .about.544), and light is detected based on whether or not the focus circle 89c is located substantially at the center of the contour line 89b. The amount of deviation of the axis in the X-axis and Y-axis directions is measured and output to the irradiation laser adjusting means 8A. The irradiation laser state inspection unit 89 measures the size (area) of the focus circle 89c, and outputs the focus position based on the size (area) to the irradiation laser adjustment unit 8A. The irradiation laser adjusting unit 8A is configured to detect the half mirrors 511 to 513 and the reflection mirrors 521 to 528 in the optical system member 50 based on the signal corresponding to the optical axis shift amount and the focus position from the irradiation laser state inspection unit 89. Feed back and adjust the placement. The lens height adjusting unit 88 and the irradiation laser adjusting unit 8A may be omitted, and the laser controller 86 may have these functions.

  In the above-described embodiment, the case where the optical axis misalignment measuring unit 85 inspects the optical axis misalignment of the laser beam and the missing pulse determining unit 82 inspects the missing pulse during laser processing (scribe processing) has been described. As shown in FIG. 4, the pulse state of the laser beam may be inspected based on the output waveform from the high-speed photodiode 94. For example, in FIG. 7, the pulse width and the pulse height of the laser light may be measured, and an alarm may be generated when an abnormality occurs in these. The pulse width of the laser light is normal when the period during which the output waveform from the high-speed photodiode 94 is equal to or greater than a predetermined value is within a predetermined range, and when it is larger or smaller than this range, the pulse width is abnormal. And outputs an alarm. The pulse height of the laser beam is normal when the maximum value of the output waveform from the high-speed photodiode 94 is within the allowable range, and when it is larger or smaller than this allowable range, the pulse height is abnormal. Judge and output an alarm. As described above, since the laser light is always sampled, the quality of the laser light such as the pulse width and the pulse height (power) can be managed in real time. If the above-described pulse omission occurs frequently, it can be determined that the laser generator 40 is deteriorated or has a lifetime.

  FIG. 8 is a view of the optical system member of FIG. 1 viewed from the lower side (substrate side). FIG. 8 shows a part of the optical system member 50 and the base plate 31. FIG. 8A is a diagram showing the positional relationship between the optical system member 50 and the base plate 31 shown in FIG. 1, and as shown in the figure, the end surface (upper end portion in the figure) of the optical system member 50 and the base are shown. The end surface (upper end portion in the figure) of the plate 31 coincides. FIG. 8B is a view showing a state in which the optical system member 50 is rotated about 30 degrees counterclockwise with respect to the base plate 31 with the center of the through hole 37 as the rotation axis. FIG. 8C is a view showing a state in which the optical system member 50 is rotated about 45 degrees counterclockwise with respect to the base plate 31 with the center of the through hole 37 as the rotation axis.

  In the solar panel manufacturing apparatus according to this embodiment, the optical system member 50 is configured to be freely rotatable with the center of the through hole 37, which is a laser light introduction hole, as the rotation axis. That is, the rotation of the optical system member 50 serving as the branching unit is controlled with the traveling direction of the vertical laser light traveling from the reflecting mirror 35 of FIG. 5 through the DOE 500 toward the half mirror 511 as the central axis. This makes it possible to variably control the angle θ formed by the laser beam branching direction and the relative movement direction of the laser beam with respect to the substrate (vertical direction in FIG. 8). In addition, although the existing techniques, such as a ball screw and a linear motor, are used as a rotational drive means of the optical system member 50, these illustration is abbreviate | omitted.

  As shown in FIG. 8, even when the angle between the laser beam branching direction and the laser beam scanning direction (vertical direction in FIG. 8) is variably controlled, the DOE 500 rotates relative to the relative movement direction of the laser beam. It is configured not to. That is, by using the DOE 500, the irradiation shape of the laser light shows an irradiation shape like a dotted square as shown in the condensing lenses 541 to 544 in FIG. Therefore, when the DOE 500 is rotated together with the rotation control of the optical system member 50, the dotted squares in the condenser lenses 541 to 544 also rotate according to the rotation amount. When the laser beam is scanned and irradiated in this state, square corners are positioned on both side ridge lines of the scribe line, and the ridge line shows a wavy shape. Therefore, as shown in FIG. 8B and FIG. 8C, scanning is performed by adopting a configuration in which the DOE 500 is not rotated even if the rotation of the optical system member 50 is controlled as in this embodiment. The direction (vertical direction in FIG. 8) and the left and right sides of the dotted square in the condenser lenses 541 to 544 coincide with each other, and both sides of the scribe line can be formed very smoothly, and the optical system member 50 is rotated. Thus, even when the pitch of the scribe lines is appropriately controlled, it is possible to form a scribe line having a smooth ridge line. In the above-described embodiment, the case where only one DOE is provided in the optical path of the laser beam has been described. However, the DOE may be provided immediately before each condensing lens after branching. Even in this case, each DOE needs to be configured not to rotate even if the rotation of the optical system member 50 is controlled. The DOE 500 can be made independent of the rotation of the optical system member 50 by being directly connected to the base plate 31 in a form separated from the optical system member 50.

  FIG. 9 is a diagram showing the relationship between the rotation amount of the optical system member and the pitch width of the scribe line. 9A shows a state where the optical system member 50 is not rotated as shown in FIG. 8A, and FIG. 9B shows a state where the optical system member 50 is rotated about 30 degrees as shown in FIG. 8B. FIG. 9C shows the state of the scribe line when the laser scribing process is performed with the optical system member 50 rotated about 45 degrees as shown in FIG. 8C. If the pitch of the scribe lines in the case of FIG. 9A is P0, the pitch P30 in the case of FIG. 9B is P0 × cos 30 °, and the pitch P45 in the case of FIG. 9C is P0 × cos 45 °. Become. As described above, the solar panel manufacturing apparatus according to this embodiment can appropriately adjust the pitch width of the scribe line to a desired value by appropriately adjusting the rotation angle of the optical system member 50. In addition, it is possible to cope with the variable pitch adjustment by enabling the rotation of the optical system that is fixed in pitch and the optical system that is not rotated.

In the above-described embodiment, only the occurrence of missing pulses is observed, but by acquiring and storing the coordinate data (position data) of the location where the missing pulses have occurred, it is possible to perform scribe line repair processing. It becomes.
In the above-described embodiment, a part of the laser beam (sampling beam) branched and output by the beam sampler 93 is directly received using the CCD camera 96 for optical axis inspection, and the optical beam is processed by image processing. The case where the deviation is inspected has been described. An image showing a state where the laser beam is received at the center of the light receiving surface of the high-speed photodiode 94 is acquired as an inspection image by the CCD camera 96 for optical axis inspection or the split type photodiode. Thus, the optical axis deviation may be inspected.
In the above-described embodiment, the case of inspecting the optical axis deviation and the missing pulse of the laser beam has been described. However, the state of the laser beam is inspected by appropriately combining the optical axis deviation, the missing pulse, the pulse width, and the pulse height. You may make it do.
In the above-described embodiment, the case where the laser beam is irradiated from the surface of the substrate 1 on which the thin film is formed to form scribe lines (grooves) in the thin film is described. However, the laser beam is irradiated from the back surface of the substrate 1. A scribe line may be formed on the thin film on the substrate surface.
In the above-described embodiment, the solar panel manufacturing apparatus has been described as an example. However, the present invention can also be applied to an apparatus that performs laser processing, such as an EL panel manufacturing apparatus, an EL panel correction apparatus, and an FPD correction apparatus.

DESCRIPTION OF SYMBOLS 1 ... Work 1a ... Silicon dioxide film 1b ... Transparent electrode layer 10 ... Base 20 ... XY table 30 ... Slide frame 31 ... Base plate 33 ... Galvano mirror 331 ... Galvano control apparatus 332 ... Beam sampler 333 ... Quadrant photodiode 33xy, 33yz ... motors 34, 35 ... reflecting mirror 37 ... through hole 40 ... laser generator 50 ... optical system member 500 ... phase type diffractive optical element (DOE)
511 to 513 ... half mirrors 521 to 528 ... reflection mirrors 531 to 534 ... shutter mechanisms 541 to 544 ... condensing lenses 52 and 54 ... length measurement system 60 for autofocus ... alignment camera device 70 ... linear encoder 80 ... control device 81 ... Branch means 82 ... Pulse missing judgment means 83 ... Alarm generation means 84 ... Reference CCD image storage means 85 ... Optical axis deviation measurement means 86 ... Laser controllers 92, 93 ... Beam sampler 94 ... High-speed photodiode 96 ... Optical axis inspection CCD camera

Claims (7)

  An optical path for reflecting the laser beam using a mirror means and introducing it to the processing position at the time of laser processing for performing predetermined processing on the workpiece by irradiating the workpiece while moving the laser beam relatively to the workpiece A part of the laser beam is branched and extracted, a deviation of the optical axis of the laser beam is detected based on the extracted laser beam, and the position of the laser beam is positioned before the branch extraction according to the detection result A laser processing method characterized in that a reflection direction of the laser beam of a mirror means is controlled.   2. The laser processing method according to claim 1, wherein a deviation of the optical axis of the laser light is detected by using a four-division photodiode means.   3. The laser processing method according to claim 1, wherein a two-axis galvanometer mirror means or two galvanometer mirror means having orthogonal drive axes are used as the mirror means for controlling the reflection direction of the laser beam. A laser processing method characterized by the above. Holding means for holding the workpiece;
Laser light irradiation means for irradiating the workpiece with laser light to perform a predetermined processing;
Mirror means for reflecting the laser light and introducing it to the laser light irradiation means;
Extraction means for branching and extracting a part of the laser beam in the optical path of the laser beam;
A light receiving means for receiving the laser light extracted by the extracting means;
Detecting means for detecting a deviation of the optical axis of the laser beam based on a signal from the light receiving means;
A laser processing apparatus comprising: control means for controlling a reflection direction of the laser light of the mirror means positioned before the extraction means according to a detection result of the detection means.   5. The laser processing apparatus according to claim 4, wherein the detection means is constituted by four-division photodiode means.   6. The laser processing apparatus according to claim 4, wherein the mirror means for controlling the reflection direction of the laser light is composed of a biaxial galvanometer mirror means or two galvanometer mirror means having orthogonal drive axes. A laser processing apparatus characterized by the above.   A solar panel manufacturing method, wherein a solar panel is manufactured using the laser processing method according to claim 1, 2 or 3, or the laser processing apparatus according to claim 4, 5 or 6.

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